Moreover, the difference remained significant in the combined cohort after controlling for confounding factors such as age, gender, tumor, histology, radio-chemotherapy, recurrent/secondary status, IDH mutation status, MGMT methylation status, and co-deletion of 1p and 19q (Figures S8B, S12; Multivariate Cox model, HR: 2.2, 95% CI: 1.7 – 2.9; Log-rank test, P = 3.7e-10). This evidence concerns the gene IDH2 and neoplasm.