In 8 to 27% of cases of de novo AML, TET2 mutations have been recognized.14, 15TET2 catalyzes the modification of 5-methylcytosine to 5-hydroxymethylcytosine in DNA which results in DNA methylation.16, 17Patients with TET2 mutations show worse prognosis in individuals having NPM1 and FLT3. This evidence concerns the gene NPM1 and acute myeloid leukemia.