IDH1 mutations involving codon 132 and IDH2 mutations involving codons 140 and 172 occur in a variety of human cancers, including acute myeloid leukemia (AML), diffuse gliomas, cholangiocarcinoma, and chondrosarcoma.4, 5, 6, 7, 8, 9, 10, 11. The gene discussed is IDH2; the disease is chondrosarcoma.