Nature Genetics 40, 51–60 (2008); published online 11 November 2007; corrected after print 23 January 2008

In the version of this article initially published, the affiliation for Stephen D Nimer was incorrect. Dr. Nimer is affiliated with the Division of Hematologic Oncology, Memorial Sloan-Kettering Cancer Center, New York, and not with Kyoto Prefectural University of Medicine. The error has been corrected in the PDF version of the article.