IDH1 and glioblastoma: Histology included astrocytoma IDH-mutant grade 3 (n = 3), oligodendroglioma IDH-mutant and 1p19q codeleted grade 3 (n = 4), astrocytoma IDH-mutant grade 2 (n = 9), oligodendroglioma IDH-mutant and 1p19q codeleted grade 2 (n = 11), and GBM IDH-wt grade 4 (n = 23).