Apo-Bovine Transferrin is an iron-free transferrin (HY-P3267) that acts as a ligand for the transferrin receptor, facilitating iron release in endothelial cells. It can bind directly to hephaestin and convert Fe2+ to Fe3+. Apo-Bovine Transferrin likely works alongside ferroportin 1 to mediate iron efflux and is applicable in neuroretina research.