IDH1 and central nervous system cancer: The results of univariate and multivariate Cox regression analyses showed that IDH1 mutation (univariate HR: 0.39, p = 5.1e‐30; multivariate HR: 0.79, p = 0.02) and HIC2 (univariate HR: 0.24, p = 8.5e‐26; multivariate HR: 0.36, p = 7.4e‐13) were independent protective factors for glioma, while age (univariate HR: 1.7, p = 1.6e‐09; multivariate HR: 1.26, p = 0.01) and grade (univariate HR: 2.6, p = 6.4e‐63; multivariate HR: 2.17, p = 1.53e‐34) were risk factors for glioma (Figure S4A).