COL4A4 and dry age related macular degeneration: Increased deposition of collagen type 1A1, collagen 4A4 and vitronectin is characteristic of Bruch's membrane and human sub-RPE deposits typically observed in dry AMD [25], while endothelial cells require extracellular matrix molecules such as COL4A4, for pericyte recruitment and vessel stabilization during angiogenesis [26, 27].