Photo of He Jiankui in a blue collard shirt who experimented to make CRISPR'd twins who were delivered last November.

To the Editor — The claim last November by He Jiankui to have engineered the first CRISPR-edited babies has ignited voluble condemnation from scientists worldwide. What, then, made this rogue researcher think that his ‘achievement’ would be welcomed? One possible factor is that He claimed that he was influenced by the words and actions of key US and UK scientists. He attended and was an invited speaker at several meetings about gene editing, including several focused on the ethical acceptability of human germline modification1. And he explicitly cited the 2017 US National Academies of Science report as support for what he did2.

The Nuffield Council on Bioethics in the UK also issued a report in July 20183. Notably, it concludes that germline genome editing could be permissible under certain circumstances. More strongly, it moves beyond the merely permissible to the ethically obligatory, saying in its final section (paragraph 5.2) that “there are moral reasons to continue with the present lines of research and to secure the conditions under which heritable genome editing would be...