IDH2 and glioma: The prognostic value of OS in each subgroup of patients with glioma was statistically significant in age ≤ 60 (HR = 2.079, 95% CI = 1.503–2.875, p < 0.001), age > 60 (HR = 1.632, 95% CI = 1.070–2.489, p = 0.023), G3 (HR = 1.849, 95% CI = 1.163–2.939, p = 0.009), astrocytoma (HR = 1.817, 95% CI = 1.070–3.087, p = 0.027), IDH-wildtype (HR = 1.40, 95% CI = 1.01–1.95, p = 0.045) and 1p/19q non-codel (HR = 1.58, 95% CI = 1.20–2.08, p = 0.001) subgroups (Fig. 4 and Fig. S4).