CXCR4 and melanoma: Melanoma tumor cells have been reported to produce multiple chemokines including CXCL1-3, CXCL5-8, CXCL10, CCL2, and CCL5; as well as the chemokine receptors CXCR1, CXCR2, CXCR3, CXCR4, CXCR6, CXCR7, CCR1, CCR2, CCR5, CCR7, CCR9, and CCR10 [41].