IDH2 and glioma: According to the 2021 WHO CNS tumor classification, the tumors were categorized as: IDH wild-type gliomas (glioblastomas, 52 cases), IDH-mutant without 1p/19q codeleted gliomas (astrocytomas, 12 cases), and IDH-mutant with 1p/19q codeleted gliomas (oligodendrogliomas, 31 cases).