Dysregulation of the epigenome is a common feature in AML, as indicated by the recent discoveries that a number of epigenome-modifying genes are mutated in AML including some involved in the regulation of DNA methylation such as IDH1/2, DNMT3A and TET2, and modulation of chromatin modifications such as ASXL1, EZH2 and others15, 16. The gene discussed is IDH1; the disease is acute myeloid leukemia.