Correction to: Nature Biotechnology https://doi.org/10.1038/s41587-019-0403-9, published online 3 February 2020.

In the version of this article initially published online, an annotation was missing for authors Melita Irving, George Coukos and Bruno E. Correia: “These authors jointly supervised this work.” The error has been corrected in the print, PDF and HTML versions of the article.