Correction to: Nature Immunology https://doi.org/10.1038/s41590-020-0623-7, published online 9 March 2020.

In the version of this article initially published, in Fig. 3f, right panel, the labels for the Ins1C:51–61 and Ins1C:51–61E peptide EC50 data were switched. The white data points correspond to Ins1C:51–61E, and the blue data points correspond to Ins1C:51–61. The error has been corrected in the HTML and PDF versions of the article.