IDH2 and astrocytoma (excluding glioblastoma): Interestingly, the IDH2 mutant/wild-type group did not show any difference in OS of GBM and OG patients (log-rank p > 0.05) but astrocytoma cases showed better survival in the IDH1 mutant group 51.5 (95% CI: 39.7–63.3) versus wild-type 21.8 months (14.1–29.5) with log rank p = 0.02.