Nat. Immunol.; 10.1038/ni.3581; corrected online 24 October 2016

In the version of this article initially published online, the symbol for the gene encoding granzyme B was incorrect (Gmzb) in the text in the third paragraph of the fourth subsection of Results and Figure 5d, and the symbol for the gene encoding granzyme A was incorrect (Gmza) in Figure 6h. These should be Gzmb and Gzma, respectively. The errors have been corrected for the print, PDF and HTML versions of this article.