MMP9 and glioblastoma: Lentivirus-mediated knockdown of HIF-1α protein and plasmid-based overexpression of CD47 protein simultaneously enhanced cell proliferation, clonogenic potential and cell migration abilities in GBM, and HIF-1α was found to regulate key pathways, including the P-PI3K/P-AKT, SOX2/OCT4 and MMP2/MMP9 pathways, in GBM.