CCL2 and breast neoplasm: Studies have also demonstrated the interaction of breast tumour‐derived EVs with Toll‐like Receptor (TLR) 2 on macrophages and the consequent activation of the NF‐κB signalling pathway in macrophages, resulting in the secretion of pro‐inflammatory cytokines such as interleukin (IL)‐6, tumour necrosis factor alpha (TNF‐α), granulocyte colony‐stimulating factor (G‐CSF), and C–C motif chemokine ligand 2 (CCL2; also known as monocyte chemoattractant protein 1, MCP‐1) (Chow et al., 2014).