Figure 1. The putative roles of CXCL12-CXCR4 axis in feline mammary carcinoma. Tumor cells expressing CXCR4 promote metastatic spread to organs showing overexpression of CXCL12 (e.g. lymph node, lungs, liver). In addition, the secretion of the ligand CXCL12 by tumor cells promotes the activation of CXCR4-CXCL12 axis locally, enhancing the primary tumor growth and inflammatory response. Finally, the production of CXCL12 by the tumor microenvironment (cancer-associated fibroblasts and myofibroblasts) enhances tumor cell mobility and invasion, and guides the recruitment of immune and bone marrow derived cells into the tumor microenvironment.