Inhibition of endogenous PGE2 production by a COX-2 inhibitor, COX-2 siRNA or an NFκB inhibitor suppressed MCP-1 expression, whereas treatment with TNF-α (to stimulate endogenous PGE2 production) or exogenous PGE2 enhanced MCP-1 expression in melanoma cells. Here, NFKB1 is linked to melanoma.