Nat. Genet. 41, 365–370 (2009); published online 15 February 2009; corrected after print 9 April 2010; retracted 27 January 2016

We have recently become aware of the presence of duplicated images in the Figures 3 and 4 and Supplementary Figures 5 and 6 in our publication Nat. Genet. 41, 365–370, 2009, that were assembled according to the specified author contributions. We therefore retract the publication for the sake of the high standards we expect for research and scientific journals. All the authors have signed this statement.