CXCL12 and breast cancer: The CXCL12 axis has been identified to induce proliferation of cell lines derived from many types of cancers, including prostate cancer (Fernandis et al., 2002), breast cancer (Ueda et al., 2006), lung cancer (Miao et al., 2007), multiple myeloma (Beider et al., 2011), and pancreatic cancer (Gao et al., 2010).