MMP12-specific inhibitor, PF-356231, inhibits cell migration and invasion in NPC cells in a dose-dependent manner. Cell migration and invasion assays were performed in NPC-TW02 (A and B) and in NPC-HK1 (C and D) cells, respectively, in the presence of different concentration of MMP12 inhibitor PF-356231 (0, 25 and 50 nM). Images were captured under 12.5x magnification. The relative fold-change in the number of migrated cells is shown, with the results from control cells given as 1.0. All data are presented as the mean ± SD from three independent experiments. *P < 0.05.