Nat. Biotechnol. 26, 753–762 (2008); published online 8 July 2008; corrected after print 9 October 2008.

In the version of this article initially published, in Table 6, two company names appeared in the incorrect columns. GlaxoSmithKline should be the Acquirer (not the Target) and Reliant should be the Target (not the Acquirer). The error has been corrected in the HTML and PDF versions of the article.