Nat. Immunol. 7, 302–310 (2006); published online 22 January 2006; corrected after print 29 July 2016

In the version of the article originally published, in the top immunoblot (loading control) in Figure 5f, the right half was incorrectly a mirror-image duplication of the left half. The correct immunoblot from a replicate experiment is now presented (along with the corresponding bottom immunoblot). The error has been corrected in the HTML and PDF versions of the article.