IDH1 and central nervous system cancer: Gliomas are the most common primary brain tumors, accounting for 80% of malignant central nervous system neoplasms [1].Recent genome-wide mutational analysis has demonstrated that the incidence of IDH1 mutations in gliomas ranges from 5% in primary glioblastoma (GBM) to 70% in anaplastic astrocytomas (AA) and 80% in secondary GBM [2]–[6].