Nat. Immunol. 8, 1227–1235 (2007); published online 30 September 2007; corrected after print 16 November 2007

In the version of this article initially published, the Author Contributions section was incorrect. The correct author contributions are as follows: R.Z and C.W designed the study, interpreted the data and wrote the manuscript; R.Z. did the experiments; N.R. and M.G. provided MK2-null mice and generated embryonic stem cells carrying a targeted allele of MK3; J.S.C.A. provided advice and MSK1-MSK2-null mice and generated MK3-null mice from the MK3 embryonic stem cells provided by N.R. and M.G. The error has been corrected in the PDF version of the article.