Nat. Struct. Mol. Biol. 20, 1214–1220 (2013); published online 22 September 2013; corrected after print 4 December 2013

In the version of this article initially published, the last sentence of the Figure 5 legend reads: “Downregulation of SOWAHC mRNA inhibits SOWAHC mRNA-CDCP1 mRNA base-pairing and thus the SOWAHC mRNA-mediated SMD of CDCP1 mRNA, an mRNA that encodes a protein that inhibits cell migration and invasion.” However, “a protein that inhibits” should have read “a protein that promotes.” The error has been corrected in the HTML and PDF versions of the article.