Thus, IDH1/2 genes are mutated in 50–80% of low-grade gliomas and secondary glioblastomas, about 20% of acute myeloid leukemia (AML), 50–60% of chondrosarcomas, about 10% of intra-hepatic cholangiocarcinoma and 10% of melanomas [8,9]. The gene discussed is IDH1; the disease is chondrosarcoma.