Secretion of free fatty acids as well as cytokines and growth factors, including Monocyte chemoattractant protein 1 (MCP-1), C-C motif chemokine ligand 5 (CCL5), and Insulin-like growth factor 1 (IGF-1), also promote breast cancer cell invasion and proliferation [29,45,46,47]. This evidence concerns the gene CCL2 and breast cancer.