CXCR2 and prostate cancer: Additionally, when CXCR2 expression is increased in prostate cancer cells, the expression of secretory factors such as VEGF, angiogenin, thrombopoietin, oncostatin M, IGF-1, CCL2/MCP-1, CCL22/MDC, and M-CSF is increased [170], namely factors that are involved in tumorigenesis.