MMP9 and glioblastoma: In contrast, siRNA down regulation of gelatinase B/MMP-9 expression induces apoptosis in human glioblastoma cells in association with Fas death receptor-mediated caspase 3 and caspase 8 cleavage, implicating gelatinase B/MMP-9 in protecting glioblastoma cells against Fas ligand-mediated apoptosis [387].