Down-regulation of MMP-9 or VEGF by siRNA transfection decreased tumor cell invasion. A, down-regulation of MMP-9 or VEGF by siRNA transfection showed low-expression of MMP-9 or VEGF protein in S100A7-transfected MDA-MB-468 cells as confirmed by Western blot analysis. B, invasion assay showing that MMP-9 or VEGF siRNA–transfected cells exhibited low penetration of cells through the Matrigel-coated membrane, compared with control siRNA-transfected cells. MMP-9, matrix metalloproteinase 9. VEGF, vascular endothelial growth factor.