CXCL8 and prostate cancer: High expression of CXCL8 was observed in several types of human cancer, such as lung cancer [20,21], breast cancer [12,13,22], colorectal cancer [14,23–25], prostate cancer [26], pancreatic cancer [27], hepatocellular carcinoma [28], head and neck squamous cell carcinoma [29], gastric cancer [30], leukemia [31], and melanoma [32–34].