CXCL8 and prostate cancer: It has been reported that IL-8 functions as a significant regulatory factor in tumor microenvironment and exerts profound effects on tumor angiogenesis, proliferation, invasion and metastasis in several cancer cells, including prostate cancer cells [40], [41], [42], Furthermore, clinical studies on advanced stages of prostate cancer cases showed that nonapical and cytoplasmic expression of interleukin-8 correlated with tumor proliferation and microvessel density [43].