Jennifer Doudna was in the audience when Dr. He presented results from his early CRISPR research at Cold Spring Harbor Laboratory in August 2016. Posting a selfie with Doudna, He gushed on social media: “CRISPR gene editing has matured!” Later, Doudna invited him to a workshop in Berkeley in January 2017. Dr. He presented his latest findings and hinted that he was thinking about bringing CRISPR into the clinic. One biologist in the audience, an amateur bluegrass musician named Steven Block, implied that “cowboy science” was the only way that this would be accomplished.

While Doudna was not briefed on He's full plans, she was part of a relatively large circle of international scientists with specific knowledge of his research trajectory. Jon Cohen, a journalist at Sciencemagazine, reports that there were “five dozen people who were not part of the study but knew or suspected what He was doing before it became public.” Some people, like Matthew Porteus of Stanford, opposed and challenged his plans, saying that an irresponsible experiment could spell an end to the field of genome editing. Others, like his postdoctoral advisor, Stephen Quake, encouraged him to proceed with caution.

James Watson, the Nobel laureate who had become infamous for his controversial remarks about race and gender, visited Dr. He's university in April 2017, as the embryo engineering experiment moved into the clinic. After Watson gave a public lecture at the Shenzhen International Precision Medical Summit, there was a public Q&A session. Dr. He asked if the possibility of rewriting the genetic code had been on his mind as he published his famous paper with Francis Crick describing the double helix structure of DNA. Watson replied that yes, of course it had. As a follow-up, Dr. He asked: What should we do with gene editing? Watson simply said: Make people better.

Dr. He's team was testing out the CRISPR technology in human embryos and then sequencing their DNA to see if it could reliably produce genetic changes. It was as if he misinterpreted a famous quote from the esteemed psychologist Abraham Maslow: “If the only tool you have is a hammer, it is tempting to treat everything as if it were a nail.” Amidst all of the other genetic engineering tools at his disposal, Dr. He was trying out CRISPR. He was searching for a good target in the genome to hit.