IGFBP2 and glioblastoma: IGFBP2 mRNA and protein were significantly upregulated in classical (C) and mesenchymal (M) GBM subtypes, when compared to the proneural (P) and neural (N) ones, based on TCGA data (Figures S5 and S6); NRAS mRNA was, instead, significantly upregulated in the N GBM subtype when compared to the other subtypes (Figure S7).