The Kaplan–Meier survival curves showed that patients reclassified from GBM to IDH1/2-mutant astrocytoma (n = 45) had significantly better survival than those with IDH1/2-wild-type GBM (n = 285), but worse survival than patients with IDH1/2-mutant astrocytoma (n = 179) (P < 0.0001; Fig. 2D). Here, IDH1 is linked to glioblastoma.