IGFBP2 and glioblastoma: IGFBP2 and NRAS were upregulated in GBM biopsies and cell lines with respect to UCs (Figure 5A and Figure S4) and their expression negatively correlated with that of circSMARCA5 (r-values = −0.58 and −0.30, p-values = 0 and 0.019, Spearman’s correlation test, respectively), and with that of their negative regulators, miR-126-3p and miR-515-5p, respectively (r-values = −0.36 and −0.34, p-values = 0.0066 and 0.010, Spearman’s correlation test, respectively) (Figure 5B).