CCL2 and neoplasm: Prior studies have noted the ability of CAAs in secreting high abundance of IL-6, IL-1β, CCL2, chemokine (C–C motif) ligand 5 (CCL5), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF) and leptin, which could enhance tumor invasion and immune escape [10, 22].