BTC and Retinal hemorrhage: Intravitreal injections of increasing doses of recombinant soluble betacellulin (0–300 ng) resulted in increased retinal hemorrhage (Fig. 2a upper panel,arrowheads) and increased retinal vascular permeability (Fig. 2b lower panel) in a dose dependent manner, similar to that induced by vascular endothelial growth factor (VEGF).