DNMT1 and myelodysplastic syndrome: The Food and Drug Administration (FDA) has approved Azacitidine and Decitabine as the first DNA methyltransferase inhibitors (DNMT inhibitors or DNMTis) for clinical application, with no important efficacy and a very high toxicity profile for myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) [151,152].