IDH1 and oligodendroglioma: Among the three major glioma subtypes, similar positive correlations were found for MGMT promoter methylation and TERT promoter VAF in IDHwt GBM (Fig. 4B), and for IDH VAF in both IDHmut astrocytoma (non-significant) and IDHmut oligodendroglioma (Fig. 4C-D).