DNMT1 and acute myeloid leukemia: Currently two DNMT inhibitors (DNMTi): 5-azacytidine (Vidaza, Celgene) and 5-aza-2′-deoxycytidine or decitabine (Dacogene, Supergen) have been approved by US Food and Drug Administration (FDA) for the treatment of acute myeloid leukemia and high risk myelodysplastic syndrome respectively (Kaminskas et al. 2005a, b).