DNMT1 and myelodysplastic syndrome: Two DNMT inhibitors, 5-azacytidine (azacytidine) and 5-aza-2′-Deoxycytidine (decitabine, DAC), have been already approved by the FDA for the treatment of some hematological diseases e.g., acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) [13].