Recent studies have assessed the prognostic significance of CXCL12 expression in various cancers, including colorectal carcinoma [38], pancreatic ductal adenocarcinoma [39], breast cancer [40], esophageal squamous cell carcinoma [41], endometrial cancer [42], germ cell tumors [43] and EOC [21,22]. Here, CXCL12 is linked to germ cell tumor.