Inhibitory effect of TFPI-2 on OSCC invasion and MMP-2 enzymatic activity. (A) In vitro cell-invasion assay. Cells that penetrated the Matrigel-coated filter were fixed, stained, and counted in at least three fields of view under a microscope. Comparison between IG and TIG groups was evaluated by Student’s t-test, and P < 0.05 (*) was considered statistically significant. Error bars indicate standard deviations. (B) The enzymatic activity of MMP-2 was determined by collagen zymography. Conditioned medium containing secreted collagenases was collected from the transduced OC2 cell cultures and subjected to collagen zymography. The position of MMP-2 (62 kDa) is indicated by an arrow.