IDH1 and chondrosarcoma: Recently, IDH1/2 mutations were found in the tumor tissue of benign cartilage tumors and in conventional chondrosarcoma and highly aggressive dedifferentiated chondrosarcomas [1, 2, 7, 9, 22, 23, 28, 34, 39, 40, 50]; however, their association with prognosis remains controversial [1, 9, 28, 32, 51], such as their use in patient treatment [10].