CXCR6 and gastrointestinal stromal tumor: Similar to CXCL16, an elevated CXCR6 expression is also associated with poorer overall survival for patients with cervical cancer [125], clear cell renal cell carcinoma [186], Ewing sarcoma family tumor [126], gastric cancer [102], gastrointestinal stromal tumors [107], hepatocellular carcinoma (p = 0.064) [48], and prostate cancer [108] (Table 5).