Nat. Immunol. 15, 118–127 (2014); published online 21 January 2014; corrected after print 10 February 2014

In the version of this article initially published online, the URL provided for the analysis and visualization program FLOCK in Table 1 was incorrect. The correct link should be https://immport.niaid.nih.gov/immportWeb/analysis/flow/displayOverview.do?method=displayFlockOverview. The error has been corrected for the print, PDF and HTML versions of this article.