To investigate the role of inflammatory and angiogenic factors in the pathogenesis of diabetic retinopathy, we determined, in diabetic patients and controls, vitreous and serum concentrations of interferon-induced protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, MIP-1β, regulated upon activation, normal T-expressed and secreted (RANTES), and vascular endothelial growth factor (VEGF). Here, CCL3 is linked to diabetic retinopathy.