Of these, 164 (26.5%) tumors were classified as IDH mutant and 1p/19q codeleted oligodendrogliomas, 252 (40.7%) tumors were classified as IDH mutant astrocytomas and the remaining 203 (32.8) tumors as IDH wildtype glioblastomas. The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).