Yet more central to cancer physiology, IL-8 forms a stronger growth enhancing role in the stem sub-population than in the non-stem population in breast cancer (Singh et al. 2013a, 2013b) hepatocellular carcinoma (Tang et al. 2012), squamous head/neck cancer (Chikamatsu et al. 2011), glioblastoma, (Infanger et al. 2013; Bonavia et al. 2012) and others. The gene discussed is CXCL8; the disease is breast carcinoma.