IDH1 and glioblastoma: In patients with age ≧ 50 years (P = 0.006), age < 50 years (P = 0.013), MGMT methylated (P < 0.005), KPS ≧ 70 (P < 0.005), CIMP unmethylated (P < 0.005), and IDH1 WT (P = 0.015), OS of GBM patients in the low-risk group was significantly better than that in the high-risk group.