Our previous study demonstrated for the first time that DJE suppressed the expression of COX-2 and mPGES-1, causing PGE2 decrease and cancer cell apoptosis in lung cancer A549 cells.(11) In the present study, we confirmed the novel functionality of Dioscorea japonica that inhibited cancer evolution via suppression of COX-2 and mPGES-1, in vivo using a model of squamous cell carcinoma of the skin. This evidence concerns the gene PTGS2 and cancer.