Nat. Genet. 44, 247–250 (2012); published online 19 February 2012; corrected after print 15 May 2012

In the version of this article initially published, the citation for the CNS+ gene set was incorrectly given as reference 17. The correct reference (Raychadhuri et al.) has been added as reference 28 in the HTML and PDF versions of the article.