Nat. Biotechnol. 29, 681–684 (2011); published online 5 August 2011; corrected after print 9 January 2012

In the version of this article initially published, Figure 1 incorrectly cites Romer et al., Plant Physiol., 2009, as the article that demonstrates “Promoter customized to bind 3 TAL effectors.” It should have cited Romer et al., Proc. Nat. Acad. Sci. USA (2009). The error has been corrected in the HTML and PDF versions of the article.