Histopathological analysis demonstrated 83 IDH-wild-type (42 males; mean age 63 years; mean overall survival 491 days; MGMT promoter methylation status: 55% methylated, 35% unmethylated, 8% unknown) and 17 IDH-mutant GBM (11 males; mean age 56 years; mean overall survival 613 days; MGMT promoter methylation status: 77% methylated, 23% unmethylated). Here, IDH1 is linked to glioblastoma.