A TET2 mutation, an unfavorable prognostic factor in AML patients with intermediate-risk cytogenetics, especially when it is combined with other adverse molecular markers [other than CEBPA (+)], occurred in 13.2% of primary AML patients and was closely associated with older age, intermediate-risk cytogenetics, NPM1 mutation and ASXL1 mutation (40). The gene discussed is NPM1; the disease is acute myeloid leukemia.