In the test of proliferative diabetic retinopathy (PDR) patients, it was found that the levels of ANGPTL-4 in the vitreous and serum of PDR patients were higher than those in the control group, and the expression level of VEGF was positively correlated with ANGPTL-4 (Lu et al., 2016). Here, ANGPTL4 is linked to proliferative diabetic retinopathy.