Translating to clinical practice, the important molecular subsets are based on the identification of a FLT3 mutation (30% of AML), NPM1 mutation (40–50% of normal karyotype AML), isocitrate dehydrogenase 1 or 2 (IDH1/2) mutations (20% of AML), and TP53 mutations (2 to 20% of AML). The gene discussed is IDH1; the disease is acute myeloid leukemia.