CXCR4 and cancer: CXCR4 (over)expression has been detected in CSCs derived from various of cancer histotypes, including pancreatic (Hermann et al., 2007), colon (Zhang et al., 2012), lung (Jung et al., 2013), breast (Dubrovska et al., 2012b) prostate (Dubrovska et al., 2012a), renal (Gassenmaier et al., 2013), and GBM (Singh et al., 2004b).