There is no N3 type of leukemia, but there is M3 type, which refers to acute promyelocytic leukemia, a type of acute myelogenous leukemia. Type M3 leukemia, also called acute promyelocytic leukemia, can be manifested by anemia, fever, susceptibility to infection, bleeding, and other signs of suppressed bone marrow hematopoiesis. Bone marrow smear may reveal predominantly granulomatous promyelocytes, which account for more than 30% of the non-red lineage nucleated cells in the bone marrow. M3 leukemia is one of the more specific types of acute myeloid leukemia, the vast majority of which have a translocation of chromosome 15 and chromosome 17 to form the PML-RARA fusion gene, which is the basis of the pathogenesis of M3 leukemia, and the molecular basis of the effectiveness of the treatment of all-trans vitexin and arsenic. Treatment of M3 leukemia can be induced remission and maintained with all-trans retinoic acid, arsenic trioxide, anthracyclines such as zorubicin, etc., under medical advice, and autologous stem cell transplantation is feasible when necessary.The prognosis of M3 leukemia is generally good and mostly curable if early death is avoided. Diagnosis and treatment should be under the supervision of a physician.