In ROP models, the introduction of hyperoxia to the retinas of newborn rats decreased VEGF levels and weakens retinal angiogenesis.32,33 Relative hypoxia of room air during the second week led to increased VEGF synthesis and pathological angiogenesis.34 During this proliferative phase of ROP, VEGF levels increase locally and systemically.35 The gene discussed is VEGFA; the disease is retinopathy of prematurity.