Together, the results from this study have identified for the first time that EGCG, a major component of green tea catechins or polyphenols, inhibit the invasive potential of melanoma cells and that involves: (i) the inhibitory effect of EGCG on endogenous COX-2 expression and successive down-regulation of PGE2 and PGE2 receptors, (ii) the inhibitory effect of EGCG on the activation of NF-κB/p65, which is the upstream regulator of COX-2, and (iii) the mesenchymal-to-epithelial transition. This evidence concerns the gene PTGS2 and melanoma.