A Chinese researcher stunned the medical world by announcing that he had altered the DNA of embryos, resulting in the births of twin girls with enhanced protection against infection. In the ensuing uproar, doctors, scientists, ethicists and governments denounced the project, demanded an investigation and the suspension of more work by the scientist until its effects and implications are better understood. Gene editing may be inevitable, but this is not the way to do science. But projects of this nature are likely to become ever more common, and the science profession and society as a whole must better prepare for this grim future.

On paper, He Jiankui looks like an ordinary scientist. He received a PhD in biophysics from Rice University and did postdoctoral research at Stanford before returning to China. He, who was according to his Stanford advisor "super bright" and "at the cutting edge of trying to apply new technologies to biology," returned to the Southern University of Science and Technology in Shenzhen, where he commenced his work.

Convinced that gene editing was inevitable, He decided to focus on HIV because the spread of that virus is a mounting problem in China. In 2016, he began efforts to figure out how to edit genes to make them immune to HIV infection. He aimed to disable the CCR5 gene that allows the HIV virus, which causes AIDS, to enter a cell. He used the CRISPR-cas9, a tool that allows the editing of genes, to change the DNA in the embryos of seven couples in which the men had HIV and the women did not, undergoing in-vitro fertilization. That project culminated in the birth of the twin girls a few weeks ago.