IDH1 and oligodendroglioma: Our cohort included 355 cases of GBM (44.5%), 179 cases of astrocytoma (22.4%), 135 cases of oligodendroglioma (17.0%), and 129 cases of other IDH1/2-wild-type gliomas (16.1%) (Fig. 1C), all classified according to the WHO classification of tumors of the CNS 2021 guidelines.