The retinal pathology in ROP has 2 main phases: phase-1 is due to exposure of the immature retina to therapeutic oxygen that switches off the hypoxia-dependent transcription of vascular endothelial growth factor (VEGF), the principle vascular growth/survival factor for vascular endothelial cells (3), causing cessation of blood vessel growth and regression of the formed vessels (4). The gene discussed is VEGFA; the disease is retinopathy of prematurity.