PDGFB and retinal disorder: Moreover, the genetic deletion of both PDGF-B and PDGFR-β in mice leads to perinatal death due to vascular dysfunction [15,16], and the ablation of endothelial-derived PDGF-B causes the reduction of retinal pericyte coverage, resulting in the change of capillary and venous diameter, microaneurysms, and proliferative retinopathy [17], thus confirming the key role played by pericytes in angiogenesis and vessel stabilization.