CXCR1 and breast cancer: Neutralizing antibodies against GCP‐2 (Verbeke et al. 2011), small molecule inhibitors for the CXCR1/CXCR2 receptors (Campbell et al. 2013), and for CREB (Xiao et al. 2010) have already been shown to reduce tumor progression in breast cancer (Ginestier et al. 2010).