In 2016, I attended a large meeting of journalists in Washington, DC. The keynote speaker was Jennifer Doudna, who just a few years before had co-invented CRISPR, a revolutionary method of changing genes that was sweeping across biology labs because it was so easy to use. With its discovery, Doudna explained, humanity had achieved the ability to change its own fundamental molecular nature. And that capability came with both possibility and danger. One of her biggest fears, she said, was “waking up one morning and reading about the first CRISPR baby”—a child with deliberately altered genes baked in from the start.  

As a journalist specializing in genetic engineering—the weirder the better—I had a different fear. A CRISPR baby would be a story of the century, and I worried some other journalist would get the scoop. Gene editing had become the biggest subject on the biotech beat, and once a team in China had altered the DNA of a monkey to introduce customized mutations, it seemed obvious that further envelope-pushing wasn’t far off. 

If anyone did create an edited baby, it would raise moral and ethical issues, among the profoundest of which, Doudna had told me, was that doing so would be “changing human evolution.” Any gene alterations made to an embryo that successfully developed into a baby would get passed on to any children of its own, via what’s known as the germline. What kind of scientist would be bold enough to try that? 

Why wait 100,000 years for natural selection to do its job? For a few hundred dollars in chemicals, you could try to install these changes in an embryo in 10 minutes.

Four weeks later, I learned that he’d already done it, when I found data that He had placed online describing the genetic profiles of two gene-edited human fetuses—that is, ”CRISPR babies” in gestation—as well an explanation of his plan, which was to create humans immune to HIV. He had targeted a gene called CCR5, which in some people has a variation known to protect against HIV infection. It’s rare for numbers in a spreadsheet to make the hair on your arms stand up, although maybe some climatologists feel the same way seeing the latest Arctic temperatures. It appeared that something historic—and frightening—had already happened. In our story breaking the news that same day, I ventured that the birth of genetically tailored humans would be something between a medical breakthrough and the start of a slippery slope of human enhancement. 

For his actions, He was later sentenced to three years in prison, and his scientific practices were roundly excoriated. The edits he made, on what proved to be twin girls (and a third baby, revealed later), had in fact been carelessly imposed, almost in an out-of-control fashion, according to his own data. And I was among a flock of critics—in the media and academia—who would subject He and his circle of advisors to Promethean-level torment via a daily stream of articles and exposés. Just this spring, Fyodor Urnov, a gene-editing specialist at the University of California, Berkeley, lashed out on X, calling He a scientific “pyromaniac” and comparing him to a Balrog, a demon from J.R.R. Tolkien’s The Lord of the Rings. It could seem as if He’s crime wasn’t just medical wrongdoing but daring to take the wheel of the very processes that brought you, me, and him into being. 

Futurists who write about the destiny of humankind have imagined all sorts of changes. We’ll all be given auxiliary chromosomes loaded with genetic goodies, or maybe we’ll march through life as a member of a pod of identical clones. Perhaps sex will become outdated as we reproduce exclusively through our stem cells. Or human colonists on another planet will be isolated so long that they become their own species. The thing about He’s idea, though, is that he drew it from scientific realities close at hand. Just as some gene mutations cause awful, rare diseases, others are being discovered that lend a few people the ability to resist common ones, like diabetes, heart disease, Alzheimer’s—and HIV. Such beneficial, superpower-like traits might spread to the rest of humanity, given enough time. But why wait 100,000 years for natural selection to do its job? For a few hundred dollars in chemicals, you could try to install these changes in an embryo in 10 minutes. That is, in theory, the easiest way to go about making such changes—it’s just one cell to start with. 

Editing human embryos is restricted in much of the world—and making an edited baby is flatly illegal in most countries surveyed by legal scholars. But advancing technology could render the embryo issue moot. New ways of adding CRISPR to the bodies of people already born—children and adults—could let them easily receive changes as well. Indeed, if you are curious what the human genome could look like in 125 years, it’s possible that many people will be the beneficiaries of multiple rare, but useful, gene mutations currently found in only small segments of the population. These could protect us against common diseases and infections, but eventually they could also yield frank improvements in other traits, such as height, metabolism, or even cognition. These changes would not be passed on genetically to people’s offspring, but if they were widely distributed, they too would become a form of human-directed self-evolution—easily as big a deal as the emergence of computer intelligence or the engineering of the physical world around us.

I was surprised to learn that even as He’s critics take issue with his methods, they see the basic stratagem as inevitable. When I asked Urnov, who helped coin the term “genome editing” in 2005, what the human genome could be like in, say, a century, he readily agreed that improvements using superpower genes will probably be widely introduced into adults—and embryos—as the technology to do so improves. But he warned that he doesn’t necessarily trust humanity to do things the right way. Some groups will probably obtain the health benefits before others. And commercial interests could eventually take the trend in unhelpful directions—much as algorithms keep his students’ noses pasted, unnaturally, to the screens of their mobile phones. “I would say my enthusiasm for what the human genome is going to be in 100 years is tempered by our history of a lack of moderation and wisdom,” he said. “You don’t need to be Aldous Huxley to start writing dystopias.”

Editing early

At around 10 p.m. Beijing time, He’s face flicked into view over the Tencent videoconferencing app. It was May 2024, nearly six years after I had first interviewed him, and he appeared in a loftlike space with a soaring ceiling and a wide-screen TV on a wall. Urnov had warned me not to speak with He, since it would be like asking “Bernie Madoff to opine about ethical investing.” But I wanted to speak to him, because he’s still one of the few scientists willing to promote the idea of broad improvements to humanity’s genes. 

Of course, it’s his fault everyone is so down on the idea. After his experiment, China formally made “implantation” of gene-edited human embryos into the uterus a crime. Funding sources evaporated. “He created this blowback, and it brought to a halt many people’s research. And there were not many to begin with,” says Paula Amato, a fertility doctor at Oregon Health and Science University who co-leads one of only two US teams that have ever reported editing human embryos in a lab.  “And the publicity—nobody wants to be associated with something that is considered scandalous or eugenic.”

After leaving prison in 2022, the Chinese biophysicist surprised nearly everyone by seeking to make a scientific comeback. At first, he floated ideas for DNA-based data storage and “affordable” cures for children who have muscular dystrophy. But then, in summer 2023, he posted to social media that he intended to return to research on how to change embryos with gene editing, with the caveat that “no human embryo will be implanted for pregnancy.” His new interest was a gene called APP, or amyloid precursor protein. It’s known that people who possess a very rare version, or “allele,” of this gene almost never develop Alzheimer’s disease. 

In our video call, He said the APP gene is the main focus of his research now and that he is determining how to change it. The work, he says, is not being conducted on human embryos, but rather on mice and on kidney cells, using an updated form of CRISPR called base editing, which can flip individual letters of DNA without breaking the molecule. 

“We just want to expand the protective allele from small amounts of lucky people to maybe most people,” He told me. And if you made the adjustment at the moment an egg is fertilized, you would only have to change one cell in order for the change to take hold in the embryo and, eventually, everywhere in a person’s brain. Trying to edit an individual’s brain after birth “is as hard a delivering a person to the moon,” He said. “But if you deliver gene editing to an embryo, it’s as easy as driving home.” 

In the future, He said, human embryos will “obviously” be corrected for all severe genetic diseases. But they will also receive “a panel” of “perhaps 20 or 30” edits to improve health. (If you’ve seen the sci-fi film Gattaca, it takes place in a world where such touch-ups are routine—leading to stigmatization of the movie’s hero, a would-be space pilot who lacks them.) One of these would be to install the APP variant, which involves changing a single letter of DNA. Others would protect against diabetes, and maybe cancer and heart disease. He calls these proposed edits “genetic vaccines” and believes people in the future “won’t have to worry” about many of the things most likely to kill them today.  

Is He the person who will bring about this future? Last year, in what seemed to be a step toward his rehabilitation, he got a job heading a gene center at Wuchang University of Technology, a third-tier institution in Wuhan. But He said during our call that he had already left the position. He didn’t say what had caused the split but mentioned that a flurry of press coverage had “made people feel pressured.” One item, in a French financial paper, Les Echos, was titled “GMO babies: The secrets of a Chinese Frankenstein.” Now he carries out research at his own private lab, he says, with funding from Chinese and American supporters. He has early plans for a startup company. Could he tell me names and locations? “Of course not,” he said with a chuckle. 

It could be there is no lab, just a concept. But it’s a concept that is hard to dismiss. Would you give your child a gene tweak—a swap of a single genetic letter among the 3 billion that run the length of the genome—to prevent Alzheimer’s, the mind thief that’s the seventh-leading cause of death in the US? Polls find that the American public is about evenly split on the ethics of adding disease resistance traits to embryos. A sizable minority, though, would go further. A 2023 survey published in Science found that nearly 30% of people would edit an embryo if it enhanced the resulting child’s chance of attending a top-ranked college. 

The benefits of the genetic variant He claims to be working with were discovered by the Icelandic gene-hunting company deCode Genetics. Twenty-six years ago, in 1998, its founder, a doctor named Kári Stefánsson, got the green light to obtain medical records and DNA from Iceland’s citizens, allowing deCode to amass one of the first large national gene databases. Several similar large biobanks now operate, including one in the United Kingdom, which recently finished sequencing the genomes of 500,000 volunteers. These biobanks make it possible to do computerized searches to find relationships between people’s genetic makeup and real-life differences like how long they live, what diseases they get, and even how much beer they drink. The result is a statistical index of how strongly every possible difference in human DNA affects every trait that can be measured. 

In 2012, deCode’s geneticists used the technique to study a tiny change in the APP gene and determined that the individuals who had it rarely developed Alzheimer’s. They otherwise seemed healthy. In fact, they seemed particularly sharp in old age and appeared to live longer, too. Lab tests confirmed that the change reduces the production of brain plaques, the abnormal clumps of protein that are a hallmark of the disease. 

“This is beginning to be about the essence of who we are as a species.”

Kári Stefánsson, founder and CEO, deCode genetics

One way evolution works is when a small change or error appears in one baby’s DNA. If the change helps that person survive and reproduce, it will tend to become more common in the species—eventually, over many generations, even universal. This process is slow, but it’s visible to science. In 2018, for example, researchers determined that the Bajau, a group indigenous to Indonesia whose members collect food by diving, possess genetic changes associated with bigger spleens. This allows them to store more oxygenated red blood cells—an advantage in their lives. 

Even though the variation in the APP gene seems hugely beneficial, it’s a change that benefits old people, way past their reproductive years. So it’s not the kind of advantage natural selection can readily act on. But we could act on it. That is what technology-assisted evolution would look like—seizing on a variation we think is useful and spreading it. “The way, probably, that enhancement will be done will be to look at the population, look at people who have enhanced capabilities—whatever those might be,” the Israeli medical geneticist Ephrat Levy-Lahad said during a gene-editing summit last year. “You are going to be using variations that already exist in the population that you already have information on.”

One advantage of zeroing in on advantageous DNA changes that already exist in the population is that their effects are pretested. The people located by deCode were in their 80s and 90s. There didn’t seem to be anything different about them—except their unusually clear minds. Their lives—as seen from the computer screens of deCode’s biobank—served as a kind of long-term natural experiment. Yet scientists could not be fully confident placing this variant into an embryo, since the benefits or downsides might differ depending on what other genetic factors are already present, especially other Alzheimer’s risk genes. And it would be difficult to run a study to see what happens. In the case of APP, it would take 70 years for the final evidence to emerge. By that time, the scientists involved would all be dead. 

When I spoke with Stefánsson last year, he made the case both for and against altering genomes with “rare variants of large effect,” like the change in APP. “All of us would like to keep our marbles until we die. There is no question about it. And if you could, by pushing a button, install the kind of protection people with this mutation have, that would be desirable,” he said. But even if the technology to make this edit before birth exists, he says, the risks of doing so seem almost impossible to gauge: “You are not just affecting the person, but all their descendants forever. These are mutations that would allow for further selection and further evolution, so this is beginning to be about the essence of who we are as a species.”

Editing everyone

Some genetic engineers believe that editing embryos, though in theory easy to do, will always be held back by these grave uncertainties. Instead, they say, DNA editing in living adults could become easy enough to be used not only to correct rare diseases but to add enhanced capabilities to those who seek them. If that happens, editing for improvement could spread just as quickly as any consumer technology or medical fad. “I don’t think it’s going to be germline,” says George Church, a Harvard geneticist often sought out for his prognostications. “The 8 billion of us who are alive kind of constitute the marketplace.” For several years, Church has been circulating what he calls “my famous, or infamous, table of enhancements.” It’s a tally of gene variants that lend people superpowers, including APP and another that leads to extra-hard bones, which was found in a family that complained of not being able to stay afloat in swimming pools. The table is infamous because some believe Church’s inclusion of the HIV-protective CCR5 variant inspired He’s effort to edit it into the CRISPR babies.

Church believes novel gene treatments for very serious diseases, once proven, will start leading the way toward enhancements and improvements to people already born. “You’d constantly be tweaking and getting feedback,” he says—something that’s hard to do with the germline, since humans take so long to grow up. Changes to adult bodies would not be passed down, but Church thinks they could easily count as a form of heredity. He notes that railroads, eyeglasses, cell phones—and the knowledge of how to make and use all these technologies—are already all transmitted between generations. “We’re clearly inheriting even things that are inorganic,” he says. 

The biotechnology industry is already finding ways to emulate the effects of rare, beneficial variants. A new category of heart drugs, for instance, mimics the effect of a rare variation in a gene, called PCSK9, that helps maintain cholesterol levels. The variation, initially discovered in a few people in the US and Zimbabwe, blocks the gene’s activity and gives them ultra-low cholesterol levels for life. The drugs, taken every few weeks or months, work by blocking the PCSK9 protein. One biotech company, though, has started trying to edit the DNA of people’s liver cells (the site of cholesterol metabolism) to introduce the same effect permanently. 

A US agency pursuing moonshot health breakthroughs has hired a researcher advocating an extremely radical plan for defeating death.

His idea? Replace your body parts. All of them. Even your brain. 

Jean Hébert, a new hire with the US Advanced Projects Agency for Health (ARPA-H), is expected to lead a major new initiative around “functional brain tissue replacement,” the idea of adding youthful tissue to people’s brains. 

President Joe Biden created ARPA-H in 2022, as an agency within the Department of Health and Human Services, to pursue what he called  “bold, urgent innovation” with transformative potential. 

The brain renewal concept could have applications such as treating stroke victims, who lose areas of brain function. But Hébert, a biologist at the Albert Einstein school of medicine, has most often proposed total brain replacement, along with replacing other parts of our anatomy, as the only plausible means of avoiding death from old age.

As he described in his 2020 book, Replacing Aging, Hébert thinks that to live indefinitely people must find a way to substitute all their body parts with young ones, much like a high-mileage car is kept going with new struts and spark plugs.

The idea has a halo of plausibility since there are already liver transplants and titanium hips, artificial corneas and substitute heart valves. The trickiest part is your brain. That ages, too, shrinking dramatically in old age. But you don’t want to swap it out for another—because it is you.

And that’s where Hébert’s research comes in. He’s been exploring ways to “progressively” replace a brain by adding bits of youthful tissue made in a lab. The process would have to be done slowly enough, in steps, that your brain could adapt, relocating memories and your self-identity.  

During a visit this spring to his lab at Albert Einstein, Hébert showed MIT Technology Review how he has been carrying out initial experiments with mice, removing small sections of their brains and injecting slurries of embryonic cells. It’s a step toward proving whether such youthful tissue can survive and take over important functions.

To be sure, the strategy is not widely accepted, even among researchers in the aging field. “On the surface it sounds completely insane, but I was surprised how good a case he could make for it,” says Matthew Scholz, CEO of aging research company Oisín Biotechnologies, who met with Hébert this year. 

Scholz is still skeptical though. “A new brain is not going to be a popular item,” he says. “The surgical element of it is going to be very severe, no matter how you slice it.”

Now, though, Hébert’s ideas appear to have gotten a huge endorsement from the US government. Hébert told MIT Technology Review that he had proposed a $110 million project to ARPA-H to prove his ideas in monkeys and other animals, and that the government “didn’t blink” at the figure. 

ARPA-H confirmed this week that it had hired Hébert as a program manager. 

The agency, modeled on DARPA, the Department of Defense organization that developed stealth fighters, gives managers unprecedented leeway in awarding contracts to develop novel technologies. Among its first programs are efforts to develop at-home cancer tests and cure blindness with eye transplants.

President Biden created ARPA-H in 2022 to pursue “bold, urgent innovation” with transformative potential.

It may be several months before details of the new project are announced, and it’s possible that ARPA-H will establish more conventional goals like treating stroke victims and Alzheimer’s patients, whose brains are damaged, rather than the more radical idea of extreme life extension. 

“If it can work, forget aging; it would be useful for all kinds of neurodegenerative disease,” says Justin Rebo, a longevity scientist and entrepreneur.

But defeating death is Hébert’s stated aim. “I was a weird kid and when I found out that we all fall apart and die, I was like, ‘Why is everybody okay with this?’ And that has pretty much guided everything I do,” he says. “I just prefer life over this slow degradation into nonexistence that biology has planned for all of us.”

Hébert, now 58, also recalls when he began thinking that the human form might not be set in stone. It was upon seeing the 1973 movie Westworld, in which the gun-slinging villain, played by Yul Brynner, turns out to be an android. “That really stuck with me,” Hébert said.

Lately, Hébert has become something of a star figure among immortalists, a fringe community devoted to never dying. That’s because he’s an established scientist who is willing to propose extreme steps to avoid death. “A lot of people want radical life extension without a radical approach. People want to take a pill, and that’s not going to happen,” says Kai Micah Mills, who runs a company, Cryopets, developing ways to deep-freeze cats and dogs for future reanimation.

The reason pharmaceuticals won’t ever stop aging, Hébert says, is that time affects all of our organs and cells and even degrades substances such as elastin, one of the molecular glues that holds our bodies together. So even if, say, gene therapy could rejuvenate the DNA inside cells, a concept some companies are exploring, Hébert believes we’re still doomed as the scaffolding around them comes undone.

One organization promoting Hébert’s ideas is the Longevity Biotech Fellowship (LBF), a self-described group of “hardcore” life extension enthusiasts, which this year published a technical roadmap for defeating aging altogether. In it, they used data from Hébert’s ARPA-H proposal to argue in favor of extending life with gradual brain replacement for elderly subjects, as well as transplant of their heads onto the bodies of “non-sentient” human clones, raised to lack a functioning brain of their own, a procedure they referred to as “body transplant.”

Such a startling feat would involve several technologies that don’t yet exist, including a means to attach a transplanted head to a spinal cord. Even so, the group rates “replacement” as the most likely way to conquer death, claiming it would take only 10 years and $3.6 billion to demonstrate.

“It doesn’t require you to understand aging,” says Mark Hamalainen, co-founder of the research and education group. “That is why Jean’s work is interesting.”

Hébert’s connections to such far-out concepts (he serves as a mentor in LBF’s training sessions) could make him an edgy choice for ARPA-H, a young agency whose budget is $1.5 billion a year.

For instance, Hebert recently said on a podcast with Hamalainen that human fetuses might be used as a potential source of life-extending parts for elderly people. That would be ethical to do, Hébert said during the program, if the fetus is young enough that there “are no neurons, no sentience, and no person.” And according to a meeting agenda viewed by MIT Technology Review, Hébert was also a featured speaker at an online pitch session held last year on full “body replacement,” which included biohackers and an expert in primate cloning.

Hébert declined to describe the session, which he said was not recorded “out of respect for those who preferred discretion.” But he’s in favor of growing non-sentient human bodies. “I am in conversation with all these groups because, you know, not only is my brain slowly deteriorating, but so is the rest of my body,” says Hébert. “I’m going to need other body parts as well.”

The focus of Hébert’s own scientific work is the neocortex, the outer part of the brain that looks like a pile of extra-thick noodles and which houses most of our senses, reasoning, and memory. The neocortex is “arguably the most important part of who we are as individuals,” says Hébert, as well as “maybe the most complex structure in the world.”

There are two reasons he believes the neocortex could be replaced, albeit only slowly. The first is evidence from rare cases of benign brain tumors, like a man described in the medical literature who developed a growth the size of an orange. Yet because it grew very slowly, the man’s brain was able to adjust, shifting memories elsewhere, and his behavior and speech never seemed to change—even when the tumor was removed. 

That’s proof, Hébert thinks, that replacing the neocortex little by little could be achieved “without losing the information encoded in it” such as a person’s self-identity.

The second source of hope, he says, is experiments showing that fetal-stage cells can survive, and even function, when transplanted into the brains of adults. For instance, medical tests underway are showing that young neurons can integrate into the brains of people who have epilepsy  and stop their seizures.  

“It was these two things together—the plastic nature of brains and the ability to add new tissue—that, to me, were like, ‘Ah, now there has got to be a way,’” says Hébert.

“I just prefer life over this slow degradation into nonexistence that biology has planned for all of us.”

One challenge ahead is how to manufacture the replacement brain bits, or what Hebert has called “facsimiles” of neocortical tissue. During a visit to his lab at Albert Einstein, Hébert described plans to manually assemble chunks of youthful brain tissue using stem cells. These parts, he says, would not be fully developed, but instead be similar to what’s found in a still-developing fetal brain. That way, upon transplant, they’d be able to finish maturing, integrate into your brain, and be “ready to absorb and learn your information.”

To design the youthful bits of neocortex, Hébert has been studying brains of aborted human fetuses 5 to 8 weeks of age. He’s been measuring what cells are present, and in what numbers and locations, to try to guide the manufacture of similar structures in the lab.

“What we’re engineering is a fetal-like neocortical tissue that has all the cell types and structure needed to develop into normal tissue on its own,” says Hébert. 

Part of the work has been carried out by a startup company, BE Therapeutics (it stands for Brain Engineering), located in a suite on Einstein’s campus and which is funded by Apollo Health Ventures, VitaDAO, and with contributions from a New York State development fund. The company had only two employees when MIT Technology Review visited this spring, and the its future is uncertain, says Hébert, now that he’s joining ARPA-H and closing his lab at Einstein.

Because it’s often challenging to manufacture even a single cell type from stem cells, making a facsimile of the neocortex involving a dozen cell types isn’t an easy project. In fact, it’s just one of several scientific problems standing between you and a younger brain, some of which might never have practical solutions. “There is a saying in engineering. You are allowed one miracle, but if you need more than one, find another plan,” says Scholz.

Maybe the crucial unknown is whether young bits of neocortex will ever correctly function inside an elderly person’s brain, for example by establishing connections or storing and sending electro-chemical information. Despite evidence the brain can incorporate individual transplanted cells, that’s never been robustly proven for larger bits of tissue, says Rusty Gage, a biologist at the Salk Institute in La Jolla, Calif., and who is considered a pioneer of neural transplants. He says researchers for years have tried to transplant larger parts of fetal animal brains into adult animals, but with inconclusive results. “If it worked, we’d all be doing more of it,” he says.

The problem, says Gage, isn’t whether the tissue can survive, but whether it can participate in the workings of an existing brain. “I am not dissing his hypothesis. But that’s all it is,” says Gage. “Yes, fetal or embryonic tissue can mature in the adult brain. But whether it replaces the function of the dysfunctional area is an experiment he needs to do, if he wants to convince the world he has actually replaced an aged section with a new section.”

In his new role at ARPA-H, it’s expected that Hébert will have a large budget to fund scientists to try and prove his ideas can work. He agrees it won’t be easy. “We’re, you know, a couple steps away from reversing brain aging,” says Hébert. “A couple of big steps away, I should say.”

He Jiankui, the Chinese biophysicist whose controversial 2018 experiment led to the birth of three gene-edited children, says he’s returned to work on the concept of altering the DNA of people at conception, but with a difference. 

This time around, he says, he will restrict his research to animals and nonviable human embryos. He will not try to create a pregnancy, at least until society comes to accept his vision for “genetic vaccines” against common diseases.

“There will be no more gene-edited babies. There will be no more pregnancies,” he said during an online roundtable discussion hosted by MIT Technology Review, during which He answered questions from biomedicine editor Antonio Regalado, editor in chief Mat Honan, and our subscribers.

During the interview, He defended his past research and said the “only regret” he had was the difficulties he had caused to his wife and two daughters. He spent three years in prison after a court found him guilty of breaking regulations, but since his release in 2022 he has sought to stage a scientific comeback.

He says he currently has a private lab in the city of Sanya, in Hainan province, where he works on gene therapy for rare disease as well as laboratory tests to determine how, one day, babies could be born resistant to ever developing Alzheimer’s disease.

The Chinese scientist said he’s receiving financial support from individuals in the US and China, and from Chinese companies, and has received an offer to form a research company in Silicon Valley. He declined to name his investors.

Read the full transcript of the event below.


Mat Honan: Hello, everybody. Thanks for joining us today. My name is Mat Honan. I’m the editor in chief here at MIT Technology Review. I’m really thrilled to host what’s going to be, I think, a great discussion today. I’m joined by Antonio Regalado, our senior editor for biomedicine, and He Jiankui, who goes by the name JK. 

JK is a biophysicist, He’s based in China, and JK used CRISPR to edit the genes of human embryos, which ultimately resulted in the first children born whose DNA had been tailored using gene editing. Welcome to you both.

To our audience tuning in today, I wanted to let you know if you’ve got questions for us, please do ask them in the chat window. We’ve got a packed discussion planned, but we will get to as many of those as we can throughout. Antonio, I think I’m going to start with you, if we can. You’re the one who broke this story six years ago. Why don’t you set the stage for what we’re going to be talking about here today, and why it’s important.

Antonio Regalado: Mat, thank you.

The subject is genome editing. Of course, it’s a technology for changing the DNA inside of individual cells, including embryos. It’s hard to overstate its importance. I put it up there with the invention of the transistor and artificial intelligence.

And why do I think so? Well, genome editing gives humans control, or at least the ability to try and direct the very processes that brought us about as a species. So it’s that profound.

Getting to JK’s story. In 2018 we had a scoop—he might call it a leak—in which we described his experiment, which, as Mat said, was to edit human embryos to delete a particular gene called CCR5 with the goal of rendering the children, of which there were three, immune to HIV, which their fathers had and which is a source of stigma in China. So that was the project.

Of course our story set off, you know, immediate chaos. Voices were raised all over the world—many critical, a few in support. But one of the consequences was that JK and his team, the parents and the doctors, did not have the ability to tell their own story—in JK’s case because he was, in fact, detained and has completed a term in prison. So we’re happy to have him here to answer my questions and those of our subscribers. JK, thank you for being here. 

Several people, including Professor Michael Waitzkin of Duke University, would like to know what the situation is with the three children. What do you know about their health, and where is this information coming from?

He Jiankui: Lulu, Nana, and the third gene-edited baby—they were healthy and are living a normal, peaceful, undisturbed life. They are as happy as any other people, any other children in kindergarten. I have maintained a constant connection with their parents.

Antonio Regalado: I see. JK, on X, you recently made a comment about one of the parents—now a single mother—who you said you were supporting financially. What can you tell us about that situation? What kind of obligations do you have to these children, and are you able to meet those obligations?

He Jiankui: So the third genetic baby—the parents divorced, so the girl is with her mother. You know, a single mother, a single-parent family—life is not easy. So in the last two years, I’m providing some financial support, but I’m not sure it’s the right thing to do or whether it’s ethical, because I’m a scientist or a doctor, and she is a volunteer or patient. For scientists or doctors to provide financial support to the volunteer or patient—it correct? Is it the right thing to do, and is it ethical? That’s something I’m not sure of. So I have this question, actually.

Antonio Regalado: Interesting. Well, there’s a lot of ethical dilemmas here, and one of them is about your publications, the scientific publications which you prepared and which describe the experiment. So a two-part question for you. 

First of all, setting the ethics aside, some people who criticized your experiment still want to know the result. They would like to know if it worked. Are the children resistant to HIV or not? So part one of the question is: Are you able to make a measurement on their blood, or is anybody able to make a measurement that would show if the experiment worked? And second part of the question: Do you intend to publish your paper, including as a preprint or as a white paper?

He Jiankui: So I always believe that scientific research must be open and transparent, so I am willing to publish my papers, which I wrote six years ago.

It was rejected by Nature, for some reason. But even today, I would say that I’m willing to publish these two papers in a peer-reviewed journal. It has to be peer-reviewed; that is the standard way to publish in a paper.

The other thing is whether the baby is resistant to HIV. Actually, several years ago, when we designed the experiment, we already collected the [umbilical] cord blood when they were born. We collected cord blood from the babies, and our original experiment design was to challenge the cord blood with the HIV virus to see whether they are actually resistant to HIV. But this experiment never happened, because when the news broke out, there has been no way to do any experiment since then. 

I would say I am happy to share my results to the whole world.

Mat Honan: Thanks, Antonio. Let me start with a question from a reader, Karen Jones. She asks, with so much controversy around breaking the law in China, she wanted to know about your credibility. And it reminds me of something that I’m curious about myself. What are the professional consequences of your work? Are you still able to work in China? Are you still able to do experiments with CRISPR?

He Jiankui: Yes, I continue my research in the lab. I have a lab in Sanya [Hainan province], and also previously a lab in Wuhan.

My current work is on gene editing to cure genetic disease such as Duchenne muscular dystrophy and several other genetic diseases. And all this is done by somatic gene therapy, which means this is not working on human embryos.

Mat Honan: I think that leads [to] a question that we have from another reader, Sophie, who wanted to know if you plan to do more gene editing in humans.

He Jiankui: So I have proposed a research project using human embryo gene editing to prevent Alzheimer’s disease. I posted this proposal last year on Twitter. So my goal is we’re going to test the embryo gene editing in mice and monkeys, and in human nonviable embryos. Again, it’s nonviable embryos. There will be no more gene-edited babies. There will be no more pregnancies. We’re going to stop at human nonviable embryos. So our goal is to see if we could prevent Alzheimer’s for offspring or the next generation, because Alzheimer’s has no cure currently.

Mat Honan: I see. And then my last question before I move it back to Antonio. I’m curious if you plan to continue working in China, or if you think that you will ultimately relocate somewhere else. Do you plan to do this work elsewhere? 

He Jiankui: Some investors from Silicon Valley proposed to invest in me to start a company in the United States, with research done both in the United States and in China. This is a very interesting proposal, and I am considering it. I would be happy to work in the United States if there’s good opportunity.

Mat Honan: Let me just remind our readers—if you do have questions, you could put them in the chat and we will try to get to them. But in the meantime, Antonio, back over to you, please.

Antonio Regalado: Definitely, I’m curious about what your plans are. Yesterday Stat News reported some of the answers to today’s questions. They said that you have established yourself in the province of Hainan in China. So what kind of facility do you have there? Do you have a lab, or are you doing research? And where is the financial support coming from?

He Jiankui: So here I have an independent private research lab with a few people. We get funding from both the United States and also from China to support me to carry on the research on the gene therapy for Duchenne muscular dystrophy, for high cholesterol, and some other genetic diseases. 

Antonio Regalado: Could you be more specific about where the funding is coming from? I mean, who is funding you, or what types of people are funding this research? 

He Jiankui:  There are people in the United States who made a donation to me. I’m not going to disclose the name and amount. Also the Chinese people, including some companies, are providing funding to me.

Antonio Regalado: I wonder if you could sketch out for us—I know people are interested—where you think all this [is] going to lead. With a long enough time frame—10 years, 20 years, 30 years—do you think the technology will be in use to change embryos, and how will it be used? What is the larger plan that you see?

He Jiankui: I would say in 50 years, like in 2074, embryo gene editing will be as common as IVF babies to prevent all the genetic disease we know today. So the babies born at that time will be free of genetic disease.

Antonio Regalado: You’re working on Alzheimer’s. This is a gene variant that was described in 2012 by deCode Genetics. This is one of these variants that is protective—it would protect against Alzheimer’s. Strictly speaking, it’s not a genetic disease. So what about the role of protective variants, or what could be called improvements to health?

He Jiankui: Well, I decided to do Alzheimer’s disease because my mother has Alzheimer’s. So I’m going to have Alzheimer’s too, and maybe my daughter and my granddaughter. So I want to do something to change it. 

There’s no cure for Alzheimer’s today. I don’t know for how many years that will be true. But what we can do is: Since some people in Europe are at a very low risk [for] Alzheimer’s, why don’t we just make some modifications so our next generation also have this protective allele, so they have a low risk of Alzheimer’s or maybe are free of Alzheimer’s. That’s my goal.

Antonio Regalado: Well, a couple of questions. Will any country permit this? I mean, genome editing, producing genome-edited children, was made formally illegal in China, I think in 2021. And it’s prohibited in the United States in another way. So where can you go, or where will you go to further this technology?

He Jiankui:  I believe society will eventually accept that embryo gene editing is a good thing because it improves human health. So I’m waiting for society to accept that. My current research is not doing any gene-edited baby or any pregnancy. What I do is a basic research in mice, monkeys, or human nonviable embryos. We only do basic research, but I’m certain that one day society will accept embryo gene editing.

Mat Honan: That raises a question for me. We’re talking about HIV or Alzheimer’s, but there are other aspects of this as well. You could be doing something where you’re optimizing for intelligence or optimizing for physical performance. And I’m curious where you think this leads, and if you think that there is a moral issue around, say, parents who are allowed to effectively design their children by editing their genes.

He Jiankui: Well, I advise you to read the paper I published in 2018 in the CRISPR Journal. It’s my personal thinking of the ethical guidelines for embryo gene editing. It was retracted by the CRISPR Journal. But I proposed that the embryo gene editing should only be used for disease. It should never be used for a nontherapeutic purpose, like making people smarter, stronger, or beautiful.

Mat Honan:  Do you not think that becomes inevitable, though, if gene-editing embryos becomes common?

He Jiankui: Society will decide that. 

Mat Honan: Moving on: You said that you were only working with animals or with nonviable embryos. Are there other people who you think are working with human embryos, with viable human embryos, or that you know of, or have heard about, continuing with that kind of work?

He Jiankui: Well, I don’t know yet. Actually, many scientists are keeping their distance from me. But there are people from somewhere, an island in Honduras or maybe some small East European country, inviting me to do that. And I refused. I refused. I will only do research in the United States and China or other major countries.

Mat Honan: So the short answer is, that sounded almost like a yes to me? You think that it is happening? Is that correct?

He Jiankui: I’m not answering that. 

Mat Honan: Okay, fair enough. I’m going to move on to some reader questions here while we have the time. You mentioned basically having society come around to seeing that this is necessary work. Ravi asks: What type of regulatory framework do you believe is necessary to ensure responsible development and applications of this technology? You had mentioned limiting to therapeutic purposes. Are there other frameworks you think should be in place?

He Jiankui: I’m not answering this question.

Mat Honan: What you think should be in place in terms of regulation?

He Jiankui: Well, there are a lot of regulations. I personally comply with all the laws, regulations, and international ethics for my work. 

Mat Honan: I see. Go ahead, Antonio. 

Antonio Regalado: Let me just jump in with a related question. You talked about offers of funding from the United States, from Silicon Valley—offers of funding to support you. Is that to create a company, and how would accepting investment from entrepreneurs to start a company change public perception about the technology?

He Jiankui: Well, it was designed as a company registered in the United States and headquartered in the United States.

Antonio Regalado: But do you think that starting a company will make people more enthusiastic or interested in this technology?

He Jiankui: Well, for me, I would certainly be more happy to get an offer from the United States [if it came] from a university or research institution. I would be happy for that, but it’s not happening. But, well, a company started doing some basic research, and that’s also a good contribution.

Antonio Regalado: Getting back to the initial experiment—obviously, it’s been criticized a great deal. And I am just wondering, looking back, which of those criticisms do you accept? Which do you disagree with? Do you have regrets about the experiment?

He Jiankui: The only regret I have is to my family, my wife and my two daughters. In the last few years, they are living in a very difficult situation. I won’t let that happen again.

Antonio Regalado: The technology is viewed as controversial. I’m talking about embryo editing. So it’s a little bit surprising to me that you would return to it. Surprising and interesting. So why is it that you have decided to pursue this vision, this project, despite the problems? I mean, you’re still working on it. What is your motivation?

He Jiankui: Our stance is always for us to do something to benefit mankind.

Antonio Regalado: Speaking of mankind, or humankind, I did have a question about evolution. The gene edits that you made to CCR5 and now are working on to another gene in Alzheimer’s—these are natural mutations that occur in some populations, you mentioned in Europe. They’ve been discovered through population genetics. Studies of a large number of people can find these genetic variations that are protective, or believed to be protective, against disease. In the natural course of evolution, those might spread, right? But it would take hundreds of thousands of years. So with gene editing, you can introduce such a change into an embryo, I guess, in a matter of minutes.

So the question I have is: Is this an evolutionary project? Is it human technology being used to take over from evolution?

He Jiankui: I’m not interested in evolution. Evolution takes thousands of years. I only care about the people surrounding me—my family, and also the patients who would come to find me. What I want to do is help those people, help people in this living world. I’m not interested in evolution.

Antonio Regalado: Mat, any other question from the audience you’d like to throw in?

Mat Honan: Yeah, let me get to one from Rez, who’s asking: What do you see as the major hurdles in advancing CRISPR to more general health-care use cases? What do you see as the big barriers there?

He Jiankui:  If you’re talking about somatic gene therapy, the bottleneck, of course, is delivery. Without breakthroughs in delivery technology, somatic gene therapy is heading toward a dead end. For the embryo gene editing, the bottleneck, of course, is: How long will it take people to accept new technology? Because as humans, we are always conservative. We are always worried about the new things, and it takes time for people to accept new technology. 

Mat Honan: I wanted to get a question from Robert that goes back to our earlier discussion here, which is: What was your initial motivation to take this step with the three children?

He Jiankui: So several years ago, I went to a village in the center of China where more than 30% of people are infected with HIV. Back to the 1990s, many years ago, people sold blood, and it did something [spread HIV]. When I was there, I saw that there’s a very small kindergarten, only designed for the children of HIV patients. Why did that happen? Other public schools won’t take them. I felt that there’s a kind of discrimination to these children. And what I want to do is to do something to change it. If the HIV patient—if their children are not just free from but actually immune to HIV, then it will help them to go back to the society. For me, it’s just like a vaccine. It’s one vaccine to protect them for a lifetime. 

Mat Honan: I see we’re running short on time here, and I do want to try to get to some more of our reader questions. I know Antonio has a last one as well. If you do have questions, please put them in the chat. And from Joseph, he wants to know: You say that you think that the society will come around. What do you think will be the first types of embryo DNA edits that would be acceptable to the medical community or to society at large?

He Jiankui: Very recently, a patient flew here to visit me in my office. They are a couple, they are over 40 years old. They want to have a baby and already did IVF. They have embryos, but the embryos have a problem with a chromosome. So this embryo is not good. So one thing, apparently, we could do to help them is to correct the chromosome problem so they can have a healthy embryo, so they can have children. We’re not creating any immunity to anything—it’s just to restore the health of the embryo. And I believe that would be a good start.

Mat Honan: Thank you, JK. Antonio, back over to you. 

Antonio Regalado:  JK, I’m curious about your relationship to the government in China, the central government. You were punished, but on the other hand, you’re free to continue to talk about science and do research. Does the government support you and your ideas? Are you a member of the political party? Have you been offered membership? What is your relationship to the government?

He Jiankui: Next question.

Antonio Regalado: Next question? Okay. Interesting. We’ll have to postpone that one for another day.

Mat, anything else? I think we’re coming up against time, and I’m wondering if we have reader questions. I have one here that I could ask, which is about the new technologies in CRISPR. People want to know where this technology is going, in terms of the methods. You used CRISPR to delete a gene. But CRISPR itself is constantly being improved. There are new tools. So in your lab, in your experiments, what gene-editing technology are you employing?

He Jiankui:  So six years ago, we were using the original CRISPR-Cas9 invented by Jennifer Doudna. But today, we are moving on to base editing, invented by David Liu. The base editing, it’s safe in embryos. It won’t cut the DNA or break it—just small changes. So we no longer use CRISPR-Cas9. We’re using base editing.

Antonio Regalado: And can you tell me the nature of the genetic change that you’re experimenting with or would like to make in these cells to make them resistant to Alzheimer’s? How big a change are you making with this base editor, or trying to make with it?

He Jiankui: So to make people protected against Alzheimer’s, we just need a single base change in the whole human 3 billion letters of DNA. We just change one letter of it to protect people from Alzheimer’s.

Antonio Regalado: And how soon do you think that this could be in use? I mean, it sounds interesting. If I had a child, I might want them to be immune to Alzheimer’s. So this is quite an interesting proposal. What is the time frame in years—if it works in the lab—before it could be implemented in IVF clinics?

He Jiankui: I would say there’s the basic research that could be finished in two years. I won’t move on to the human trial. That’s not my role. It’s determined by society whether to accept it or not. And that’s the ethical side. 

Antonio Regalado: A last question on this from a reader. The question is: How do you prove the benefits? Of course, you can make a genetic change. You can even create a person with a genetic change. But if it’s for Alzheimer’s, it’s going to take 70 years before you know and can prove the results. So how can you prove its medical benefit? Or how can you predict the medical benefit?

He Jiankui: So one thing is that we can observe it in the natural world. There are already thousands of people with this mutation. It helps them against Alzheimer’s. It naturally exists in the population, in humans, so that’s a natural human experiment. And also we could do it in mice. We could use Alzheimer’s model mice and then to modulate DNA to see the results.

You might argue that it takes many years to develop Alzheimer’s, but in society, we’ve done a lot with the HPV vaccine against certain women’s cancers. Cancer takes many years to happen, but they take the HPV vaccine at age eight or seven.

Mat Honan: Thank you so much. JK and Antonio, we are slightly past time here, and I’m going to go ahead and wrap it up. Thank you very much for joining us today, to both of you. And I also want to thank all of our subscribers who tuned in today. I do hope that we see you again next month at our Roundtable in August. It’s our subscriber-only series. And I hope you enjoyed today. Thanks, everybody. 

Antonio Regalado: Thank you, JK.

He Jiankui: Thank you.