Moreover, CXCL12 is expressed at high levels in bladder cancer (Yang et al., 2015a), gastric cancer (Ishigami et al., 2007), hepatocellular carcinoma (Ghanem et al., 2014), prostate cancer (Zhang et al., 2008), lung cancer (Imai et al., 2010), and many other human tumors (Sakai et al., 2012; Qiao et al., 2016; Teng et al., 2016). Here, CXCL12 is linked to prostate cancer.