5-Aza-2′-deoxycytidine is a DNA-hypomethylating agent, which stimulates differentiation and apoptosis of leukemic cells. It is a 2′-deoxycytidine analogue. 5-Aza-2′-deoxycytidine is used to treat chronic myelomonocytic leukemia, refractory anemia, myelodysplastic syndrome and acute myeloid leukemia.