EDNRA and glaucoma: Because Edn ligands were upregulated in DBA/2J glaucoma [3, 5, 7], pan-antagonism of EDN signaling lessened RGC loss after ocular hypertensive insults [5, 6], and EDN1-induced RGC death was driven by vascular mural cell-expressed EDNRA (Fig. 5), it is possible that chronic vascular pathology or vasoconstriction is an important mediator of RGC death in glaucoma.