TGFB1 and diabetic retinopathy: In addition, study found that the combination of TGF-β and TGF-β receptors on retinal vascular endothelial cells increased the basement membrane of capillaries, which lead to lumen stenosis and blood flow changed, resulted in retinal ischemia, hypoxia, and neovascularization in the late stage of diabetic retinopathy [31].