Nat. Cell Biol. 12, 1101–1107 (2010); published online 10 October 2010; corrected after print 25 February 2015

In the version of this Letter originally published the first lin-28 targeting morpholino oligonucleotide should have read: 5′-GGGCATCTTTATGATTTAGCCTTCT-3′. This has been corrected in all online versions of the Letter.