G2 glioma post-operative volume (cm3) i) Oligodendroglioma (9 vs. ≥9) ii) IDH mutant astrocytoma (1 vs. ≥1) iii) IDH wt astrocytoma (1 vs. ≥ 1). The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).