To further detect the relationship between inhibition of PMS on cancer cell lines and the activity of MMP, the culture media of cells treated with solvent without PMS (control) or with 125 and 250 μg/mL PMS or 100 and 200 μg/mL Catechin for 24 h and/or 36 h were analyzed by gelatin zymography assay, the activity of MMP9 was dramatically decreased by PMS both in MDA-MB-231 cells and 4T1 cells shown as Fig. 3f; the activity of MMP2 was also decreased, but the decrease was less than that of MMP9 (Fig. 3f). The gene discussed is MMP9; the disease is cancer.