CCL2 and renal fibrosis: Once the RAS is activated in diabetic kidneys, it may induce the generation of growth factors or cytokines such as TGF-β, vascular endothelial growth factor (VEGF), and monocyte chemotactic protein 1 (MCP-1), which may directly or indirectly lead to renal fibrosis, oxidative stress and podocyte apoptosis [175].