HGF and retinopathy of prematurity: The oxygen-induced retinopathy (OIR) mouse model was chosen for these studies because it is a well‐established model for studying pathological angiogenesis in the eye (26) and, similar to human ischemic retinopathies (e.g., ROP and PDR), neovascular pathology in this model involves multiple growth factors, including VEGF, bFGF, HGF, and IGF-1 (27–30).