. Author manuscript; available in PMC: 2021 Jul 28.
Published in final edited form as: Nat Immunol. 2021 Jan 28;22(3):312–321. doi: 10.1038/s41590-020-00859-0
Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms