CCL2 and diabetic kidney disease: Several studies suggested that cytokines, such as tumor necrosis factor-α (TNF- α) and interleukin-6 (IL-6) [11, 24, 25], and chemokines, e.g. monocyte chemoattractant protein-1 (MCP-1), and C-X-C chemokine ligand 16 (CXCL16) [26], were involved in the inflammatory process of DKD.