Hotspot mutations in IDH1 and IDH2 have subsequently been shown to occur in at least 13 types of cancer, including 70% of malignant gliomas, 30% of AML and 5–25% of cholangiocarcinomas [5,9,10,11,15,16,17,18,19]. The gene discussed is IDH2; the disease is acute myeloid leukemia.