IDH1 and oligodendroglioma: However, patients with IDH-mutant/codeleted oligodendroglioma had longer survival times after transformation than patients with IDH-mutant/non-codeleted astrocytoma (Supplementary Figure S2C; 28.3 months vs. 10.8 months; HR, 0.67; P = 0.041); the PFS after transformation was also longer in IDH-mutant/codeleted oligodendroglioma (Supplementary Figure S2D; P = 0.068).