CCL2 and diabetes mellitus: Recent studies have shown that the expression of cytokines (IL-1β, IL-6, IL-8, TNF-α, and monocyte chemotactic protein 1 (MCP-1)), chemokines (Cylco-oxygenase-2 (COX-2)), and other factors (vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), insulin-like growth factor (IGF-1), basic fibroblast growth factor (bFGF), and hepatocyte growth factor (HGF)) is increased in diabetes and that the levels of these molecules are particularly elevated in the ocular fluid of diabetic patients [66,67,68,69].