HIF1A and glioblastoma: miR-23b, highly expressed in various GBM cell lines (U373, A172, LN229, U87, LN428, LN308) and in tumor tissue samples, binds to the 3′UTR of the VHL gene, inhibiting its expression and enhancing β-catenin/Tcf-4 activity and the HIF-1a/VEGF pathway and leading to enhanced invasion and tumor cell proliferation [83].