The SDF-1α/CXCR4 axis belongs to this class of mediators and recent studies have shown that inhibition of CXCR4 with antibodies, peptide antagonists or siRNA all reduce metastasis in several solid tumors, including breast [8], [36], [37], [38], melanoma [12], [39], pancreas [40], prostate [41] and colon [42] cancers. Here, CXCR4 is linked to melanoma.