Efficacy and Safety of ATO Plus ATRA in Nucleophosmin-1 Mutated Acute Myeloid Leukemia

Inclusion Criteria: 1. Age of 14 to 55 years old; 2. Patients that meet the diagnostic criteria(WHO 2008 criteria) of AML (except APL subtypes) and with NPM1-mutated. 3. Reached CR after induction regimen. 4. ECOG score of ≤ 2; 5. Patients with eligible laboratory examination including liver,renal and heart function. 6. Adult patients are willing to participate in the study and sign the informed consent by themselves or by their immediate family. Patients under 18 years old willing to participate should have their legal guardians sign the informed consent. Exclusion Criteria: 1. Secondary leukemia. 2. Patients had other tumor at active stage or had received radiotherapy or chemotherapy in the last 6 months due to other tumor. 3. Patients with other blood diseases(for example, haemophiliacs) are excluded.However, patients with abnormal blood count, but with undiagnosed MDS or MPD patients are included. 4. Acute panmyelosis with myelofibrosis and myeloid sarcoma patients; 5. With BCR-ABL fusion gene; 6. Pregnant or lactating women; 7. With ineligible renal or liver function; 8. With active cardiovascular disease; 9. Severe infection disease including uncured tuberculosis pulmonary aspergillosis; 10. AIDS; 11. Patients had central nervous system involvement when they were diagnosed as AML. 12. Patients with epilepsy or dementia or other mental disease who couldn't understand or follow the research. 13. Drugs, medical, mental or social situation may distract patients from following the research or being evaluated the results. 14. Patients with other factors which were considered unsuitable to participate in the study by the investigators.