Recently, the SP1 mRNA was shown to be expressed at high levels in the epiretinal membranes of subjects with proliferative diabetic retinopathy (PDR), and the SP1 protein colocalized with VEGF [77], suggesting that SP1 may be involved in the mechanism regulating Robo4 expression under hyperglycemic conditions. The gene discussed is SP1; the disease is proliferative diabetic retinopathy.