OLIG2 and glioblastoma: In Verhaak et al. [37], GBM was classified into four subtypes depending on the marker genes: “proneural,” “neural,” “classical,” and “mesenchymal.” It was observed that marker genes DLL3, NKX2–2, SOX2, ERBB3, and OLIG2 were overexpressed in the proneural subtype; marker genes FBXO3, GABRB2, SNCG and MBP were overexpressed in the neural subtype; FGFR3, PDGFA, EGFR, AKT2, and NES were overexpressed in the classical subtype; and CASP1, CASP4, CASP5, CASP8, ILR4, CHI3L1, TRADD, TLR2, TLR4, and RELB were overexpressed in the mesenchymal subtype.