Nat. Protoc. 9, 1255–1281 (2014); doi:10.1038/nprot.2014.072; published online 8 May 2014; corrected after print 16 January 2015

In the version of this article initially published, the final concentration of tamoxifen used in Step 53 of the Procedure was listed as 1 mM; it should be 1 μM. The error has been corrected in the HTML and PDF versions of the article.