Nat. Genet. 43, 189–196 (2011); published online 23 January 2011; corrected after print 29 March 2011
In the version of this article initially published, the authors should have acknowledged that the work was also funded by a grant from the European Union (EU-SYSCILIA) to E.E.D., C.A.J., P.L.B. and N.K. The error has been corrected in the HTML and PDF versions of the article.
The online version of the original article can be found at 10.1038/ng.756