CCL2 and cancer: Interleukin 6 (IL-6), a well-researched cytokine found in high serum concentrations in many cancer patients (29) and is also produced through cancer cells (30), is known to induce the secretion of other cytokines such as IL-8 (CXCL8), vascular endothelial growth factor (VEGF), and CCL2 (monocyte chemoattractant protein 1, MCP-1), altogether exerting pro-tumoral effects in an autocrine and paracrine manner (31).