There is no such type as N3, which generally refers to acute promyelocytic leukemia (APL, also known as M3 subtype), which is an acute myeloid leukemia. The treatment of leukemia M3 high-risk type is mainly to induce remission by retinoic acid and sodium arsenite, along with chemotherapy and intrathecal drug injection to prevent central neuropathy. Acute promyelocytic leukemia is currently the type of acute leukemia with the best prognosis, and can be divided into 3 categories: low-risk, intermediate-risk and high-risk. Treatment of the high-risk type mainly includes induction of remission therapy and some treatments after remission. Drugs include retinoic acid and arsenite, and chemotherapeutic drugs such as zorubicin and cytarabine need to be added. In addition, some patients may develop central nervous system infiltration. High-risk patients need to be treated with intrathecal drug injections, and drugs include methotrexate to prevent CNS leukemia. Once the diagnosis is confirmed, standardized treatment should be carried out as early as possible under the guidance of a physician to minimize the adverse effects of the disease.