CCL2 and kidney disorder: Meanwhile, activated resident macrophages and renal parenchymal cells such as glomerular podocytes, mesangial cells and tubular epithelial cells in DN secrete chemokines such as C-C Motif Chemokine Ligands 2 &5 (CCL2, CCL5) (37) and macrophage colony-stimulating factor 1 (CSF-1) (38), which induce circulating monocytes (Ly6Chigh monocytes and Ly6Clow monocytes) to form the infiltrating macrophages in kidney and finally contribute to pathogenesis of kidney diseases (28).