IDH1 and astrocytoma (excluding glioblastoma): GBM exhibited the highest pathway co-alterations (mean: 2.17 pathways affected; median: 2), followed by IDH1/2-mutant astrocytomas (mean: 1.40; median: 1) and oligodendrogliomas (mean: 0.42; median: 1) (Fig. 4E).