CXCR6 and pancreatic ductal adenocarcinoma: Analyses of CXCR6 expression show that the tumor has a higher expression compared to adjacent non-cancerous tissues, especially in tumors such as bladder cancer [177], breast cancer [31], gastric cancer [102,118], gastrointestinal stromal tumors [107], glioblastoma multiforme [134], hepatocellular carcinoma [32,33], non-small cell lung cancer [77], ovarian cancer [27,113,128], osteosarcoma [103], pancreatic ductal adenocarcinoma [87,106,184], prostate cancer [116,175], and schwannomas [101].