For example, mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in a subset of acute myeloid leukemia (AML) patients and IDH2 mutant leukemic cells produce elevated levels of the oncometabolite d-2-hydroxyglutarate (D2-HG) (17, 18). The gene discussed is IDH1; the disease is acute myeloid leukemia.