Nat. Genet. 48, 206–213 (2016); published online 14 December 2015; corrected after print 8 February 2016

In the version of this article initially published, the accession code for the ATAC-seq data was omitted. These data have been deposited in the European Nucleotide Archive under accession ERP011141. The error has been corrected in the HTML and PDF versions of the article.