,13, 14, 15, 16, 17, 18 The IDH mutations are also prevalent in certain cartilaginous and bone tumors (20%–80%),19, 20, 21, 22, 23, 24, 25, 26 acute myeloid leukemia (AML) (15%–30%),8,27, 28, 29, 30, 31, 32, 33, 34 intrahepatic cholangiocarcinoma (ICC) (6%–30%),35, 36, 37, 38, 39, 40, 41, 42, 43 angioimmunoblastic T cell lymphoma (20%–30%),44, 45, 46, 47 sinonasal undifferentiated carcinoma (35%–80%),48, 49, 50 and solid papillary carcinoma with reverse polarity (>77%).51 The gene discussed is IDH1; the disease is acute myeloid leukemia.