SEMA3A and diabetic retinopathy: Moreover, SEMA3A is pro-apoptotic for endothelial cells in vitro (Guttmann-Raviv et al., 2007, Klagsbrun and Eichmann, 2005), raising the possibility that SEMA3A blockade might also promote endothelial survival in diseases with vascular drop-put, such as diabetic retinopathy.