However, despite their known cytotoxicity against MLL‐rearranged ALL cells in vitro [7, 10, 17, 18], preclinical in vivo activity studies of another pivotal class of epigenetic drugs, that is, the DNA methyltransferase inhibitors (DNMTi), such as decitabine and 5‐azacytidine, are limited. This evidence concerns the gene KMT2A and acute lymphoblastic leukemia.