The Chinese scientist who ignited a backlash over creating the world’s first genetically-altered babies is undeterred by the global condemnationthat his work has sparked and believes history will be on his side when the dust settles.

He Jiankui, a researcher in the southern Chinese city of Shenzhen, was a virtual unknown in the world of genetics research and to others outside it. That changed this week after he said he had altered the genes of a pair of twin girls while they were embryos in a bid to make the recently-born babies resistant to infection by the virus that causes AIDS.

The soft-spoken outsider didn’t just get instant fame. He was rebuked by his university, other scientists, and even a government official, who said that any gene editing for fertility purposes was unlawful. A group of 122 Chinese scientists issued a joint statement decrying He’s actions as “madness” and asked the government to regulate the work.

When the mild-mannered researcher got on stage at an international genetics conference in Hong Kong Nov. 28 to share data and details about this project, he spoke softly and haltingly, with a tad of nervousness. Hestartedby apologizing for the furor in the scientific community and said a news leak had forced him to prematurely move ahead with public announcements of his project.

Then, He stuck to his ground. “I feel proud,” he said discussing the case of the twins who were given the pseudonymsLulu and Nana, whose genes he had edited. He also disclosed that there may be a second“potential pregnancy” with a gene-altered embryo, though it was unclear from his answer whether that pregnancy was still viable.

To get him to this controversial breakthrough, He worked almost alone. His research team appears to consist of one other fully-qualified scientist, the embryologist Qin Jinzhou, who conducted the actual gene surgery and in-vitro fertilization, according to a YouTubevideoposted earlier in the week explaining his project. The scientist, a soccer fan in his mid-thirties used a technology called Crispr, a state-of-the-art tool now widely used for the modification of genes in research.

He denied that he had worked in secrecy, in response to a question at the conference, and insisted all the parents in the trial were well-educated and understood the risks in the study.

William Hurlbut, an adjunct professor in neurobiology at the Stanford Medical School whom He consulted with over the past two years, said he knew the researcher was headed in that direction but didn’t know he had actually implanted edited embryos. “I challenged him at every level and I don’t approve of what he did,” Hurlbut said.

He seems to have anticipated some of the backlash, if not the severity of it. “I understand my work will be controversial, but I believe families need this technology, and I’m willing to take the criticism for them,” He said in one of the YouTube videos.

“We believe ethics are on our side of history,” He said in another video described by ScienceNet.cn, a publication of China Science Daily which is backed by the Chinese Academy of Sciences.

There’s little clue in his background that He would become controversial for a first-in-the-world human experimentation. He’s earlier work in the U.S. was largely theoretical and focused on biophysics and computational genomics, according to published papers and a US researcher who worked with him in the past.

One of his first academic papers on Crispr was published in 2010 by a physics journal and focused on a theoretical model of how bacteria use gene-editing to defend themselves. During post-doctoral work at Stanford, his research focused on computational genomics, according to the researcher, who described He as bright, ambitious, outgoing and entrepreneurial.

He now faces at least three investigations in China and calls from prominent Chinese researchers for him to be punished. A senior Chinese government official has said his work is unlawful.

The SUSTCsaidit was “shocked” at the news of He’s actions, adding that the researcher has been on unpaid leave since February. He said the university was unaware of his lab’s work

Harmonicare Medical Holdings Ltd., which owns the Shenzhen hospital that He said gave approval for the project, said in a filing Tuesday that it believed signatures on an application to the hospital’s medical ethics committee had been forged.

The controversial researcher rose to prominence in China by designing fast and cheap gene-sequencing machines through his start-up Direct Genomics, based in Shenzhen. Sina.com, an established Chinese news publication, reported in April that Direct Genomics received 218 million yuan in venture-capital funding that month.