Nat. Biotechnol. 35, 31–34 (2017); published online 5 December 2016; corrected after print 12 January 2017

In the version of this article initially published, in Fig. 2j, the percentage for the targets Mecp2, Nlgn3, and Drd1 should be 15.2%, not 16.9%; the same error appeared in the main text, next to last paragraph, “Our results show that 17%...” should be “Our results show that 15%....” In the Fig. 2 legend, KASH should be spelled out as “KASH, Klarsicht ANC1 Syne1 homology...” (not “KASH ANC1, Syne homology...”). The errors have been corrected in the HTML and PDF versions of the article.