SMAD4 and glioblastoma: Although in our results we demonstrated that overexpression of miR-301a-3p repressed SMAD4 expression through direct binding to its 3′UTR, there were still other miRNA consensus in the SMAD4 3′UTR (e.g., sites for miR-34a, miR-146a, and miR-199a, which have been identified as negative regulators of SMAD4 in gastric cancer and glioblastoma) [40, 41, 42].