DNMT1 and myelodysplastic syndrome: Currently two DNMT inhibitors (DNMTi), 5-azacytidine (azacitidine) and 5-aza-2′-deoxycytidine (decitabine) have been approved by Food and Drug Administration (FDA) and European Medicines Agency (EMA) for the treatment of myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and chronic myelomonocytic leukemia (CMML) (Constantinides et al., 1978; Jones et al., 2019).