Correction to: Nature Immunology https://doi.org/10.1038/ni.3816 (2017); published online 14 August 2017.

In the version of this article initially published, in second paragraph of the second subsection of Results (‘Peripheral licensing of CD4+ TH17 cells in Tbx21−/− hosts’), the figure citation (‘Fig. 1c’) in the sentence that begins “In addition to” was incorrect. The correct citation is ‘Fig. 1d’.