The relapse rate of leukemia M3 is less than 10%. Leukemia M3 is acute promyelocytic leukemia, which is the best type of leukemia with the best treatment results and the only type of leukemia that can be completely cured without allogeneic hematopoietic stem cell transplantation. In the past, due to the lack of effective drug treatment, the mortality rate of leukemia M3 was the highest type, and patients often died due to severe bleeding in the early stages. Since our medical doctors discovered retinoic acid and arsenite, which can be used to treat acute promyelocytic leukemia, the treatment of M3 has been revolutionized because retinoic acid can target and interrupt the fusion genes formed on chromosomes 15 and 17, thus effectively changing the effectiveness of the treatment, and the discovery of arsenite has also added useful therapeutic methods for the treatment of M3. Nowadays, the cure rate of acute promyelocytic leukemia is more than 90% through arsenite, retinoic acid and chemotherapy, and the relapse rate is also very low.