CXCL8 and melanoma: CXCL8 has been shown in many studies to correlate with tumour burden; the levels of CXCL8 in the serum of tumour-bearing mice and humans fall following surgical excision [118], patients with brain metastasis express high levels of CXCL8 in cerebrospinal fluid [119,120], and CXCL8 has been shown to be higher in models of BRAF inhibitor (BRAFi)-resistant melanoma [121].