Nature 506, 328–333 (2014); doi:10.1038/nature13038

Author Fouad Yousif (of the Ontario Institute for Cancer Research, Toronto, Canada) should have been included in the author list after Andrew M. K. Brown with affiliation number 7 and listed in the Author Contributions as performing and analysing targeted sequencing; these omissions have been corrected in the online versions of this Article. In addition, in the legend to Fig. 1a, “Somatic mutations in DNMT3a (*, R882H; †, R137C)” should read “Somatic mutations in DNMT3a (*, R882H; †, R326C)”.