Besides different histology of oligodendroglioma and glioblastoma, the two brain tumors showed different molecular profiles of oligodendroglioma (i.e. IDH1 R132H mutation, combined 1p/19q loss, TERT C250T mutation) and glioblastoma (i.e. IDH1 wildtype, retained 1p/19q, TERT C228T mutation), respectively. Here, IDH1 is linked to oligodendroglioma.