STAT: He Jiankui, embryo editing, CCR5, the London patient, and jumping to conclusions
Henry T. Greely, professor at Stanford University

“When He Jiankui announced the birth of twin girls whose DNA he had modified when they were embryos using the CRISPR gene-editing tool, he justified his actions on the ground that he had given the two girls lifetime immunity from HIV infection. The Chinese scientist claimed that he had altered a gene called CCR5, which allows the AIDS-causing virus to infect an important class of cells in the human immune system. Not only was He ethically wrong in doing this work, but its scientific basis was even weaker than generally recognized. … Many scientific commentators, as well as He himself, quickly jumped at the idea that people without functioning CCR5 proteins cannot become HIV infected. That’s not correct. … There is good evidence that the absence of functional CCR5 proteins is not completely protective against HIV. … Would a serious advance review of He’s experiment have caught this issue? I can only hope so. It certainly should have if the reviewing group included expertise in HIV infection and not just in CRISPR editing. This is a crucial lesson in the importance of a probing prior review before any experiment involving human subjects and especially before any first-in-human experiment. It is also a sobering lesson … about retrospective review of such experiments. Nature is complicated, viruses are tricky, assumptions are dangerous…” (4/15).