For example, the expression of CXCR4 on melanoma cells was associated with increased rates of metastasis and patient mortality (Longo-Imedio et al, 2005), whereas another study suggests that interleukin-8 (IL-8) and its two chemokine receptors CXCR1 and CXCR2 might promote prostate cancer progression through autocrine signalling of prostate cancer cells (Murphy et al, 2005). This evidence concerns the gene CXCR1 and prostate cancer.