The promise of targeting PMTs for cancer treatment has been highlighted by the successful development of chemical inhibitors against DOT1L for MLL leukemia (Daigle et al., 2011) and EZH2 for B-cell lymphoma carrying EZH2-activating mutations (Knutson et al., 2012, McCabe et al., 2012); these are now entering phase I clinical trials. This evidence concerns the gene DOT1L and cancer.