Nat. Med. 18, 883–891 (2012); published online 27 May 2012; corrected after print 5 October 2016

In the version of this article initially published, the upper and middle panels on the left-hand side in Figure 4a were interchanged, and the GAPDH loading panel in Supplementary Figure 6 was incorrect owing to an error in assembling the figures. The original western blot was rescanned to generate the correct GAPDH loading panel for Supplementary Figure 6. A new western blot was scanned to generate the bottom panel on the left-hand side in Figure 4a because the authors could not find the original western blot of the GAPDH loading panel. The errors have been corrected in the HTML and PDF versions of the article.