IDH2 and astrocytoma (excluding glioblastoma): Presently, gliomas are grouped into five main molecular subgroups: GBM IDH-wild type, GBM IDH-mutant, astrocytoma IDH-wild type, astrocytoma IDH-mutant, oligodendroglioma IDH-mutant, and 1p/19q-codeleted [1,5].