CCL2 and cancer: It has been reported that toll-like receptor (TLR)-mediated signaling plays a pivotal role in cancer progression through autophagy induction and the production of cytokines such as interleukin-6 (IL-6), chemokine (C-C motif) ligand 2 (CCL2/MCP-1), chemokine (C-C motif) ligand 20 (CCL20/MIP-3α), vascular endothelial growth factor A (VEGFA), and matrix metallopeptidase 2 (MMP2) [7].