A Chinese court has sentenced the scientist behind the world’s first gene-edited babies, He Jiankui, to three years in prison, saying that the researcher’s team “crossed the bottom line of ethics.” Alongside his prison sentence, The Guardian reports that He was also fined 3 million yuan (around $430,000).

He Jiankui was sentenced alongside two colleagues. Zhang Renli was fined 1 million yuan (around $143,000) and sentenced to two years in prison, while Qin Jinzhou was fined 500,000 yuan (around $71,000) and sentenced to 18-months in prison, with a two-year reprieve.

“The three accused did not have the proper certification to practice medicine, and in seeking fame and wealth, deliberately violated national regulations in scientific research and medical treatment,” the court said in comments that were reported by state news agency Xinhua.

The experiment was intended to make the babies resistant to HIV

He Jiankui claimed to have helped make the world’s first genetically edited babies — twin girls Lula and Nana — back in November 2018 using the gene-editing tool CRISPR/Cas9. This kind of work is banned in the US and other countries due to the ethical concerns of manipulating human embryos, as well as the risk the work poses to other genes, where it can create unintended side-effects that could be passed on to future generations. The scientific community was fiercely critical of the work, and He was subsequently fired from his university position at the Southern University of Science and Technology in Shenzhen.

Beyond the ethical implications, analysis of He’s work suggests that his efforts may have actually put their health at risk. The experiment aimed to make the babies immune to HIV by altering the CCR5 gene, which is believed to affect resistance to HIV. Although everyone has two copies of each gene (one from each parent), researchers pointed out that He only edited one copy of the gene. One geneticist said there are “all kinds of glitches” with the way the work was carried out, and another said that the babies probably aren’t HIV-resistant as a result.

“The claim they have reproduced the prevalent CCR5 variant is a blatant misrepresentation of the actual data and can only be described by one term: a deliberate falsehood,” Fyodor Urnov, a genome-editing scientist and the University of California, told MIT Technology Review in response to the research.