C1QTNF3 and non-proliferative diabetic retinopathy: Although retinal neovascularization is a severe complication in DR, in this study, we focused on CTRP3′s effect on the early stage of diabetic DR (NPDR), when neovascularization did not occur, but CTRP3 can ameliorate the leakage of iBRB as manifested in Figure 2A,B with FITC-Dextran tracing.