The signalling pathways show that CD146 regulates the metastasis and invasion of melanoma. A. A presumed model for the PAR1-PAFR-CD146 signalling axis in human melanoma cells is shown. PAR1 works in concert with PAFR to activate PAFR-induced phosphorylation of CREB and to recruit CREB and Sp1 to the promoter of CD146, which triggers CD146 expression in metastatic melanoma. B. CD146 contributes to the acquisition of an invasive phenotype of melanoma. CD146 regulates the expression of Id-1 and binds to the Id-1 promoter. Id-1 overexpression, in turn, results in increased binding of both Ets-1 and Sp1 to the MMP-2 promoter and further promotes MMP-2 expression.