IDH1 and glioblastoma: Within the latter category, these 112 cases included the following subsets: 99 cases of glioblastoma, IDH-wildtype with histological features of GBM; 9 cases with lower-grade histological features but meeting molecular criteria for GBM, IDH-wildtype; 3 cases of pediatric-type diffuse hemispheric glioma, H3G34-mutant, and 1 case of IDH-wildtype astrocytoma with grade 3 histological features, NOS (i.e. not meeting molecular criteria for GBM).