Multiple variants in vascular endothelial growth factor (VEGFA) are risk factors for time to severe retinopathy in type 1 diabetes: the DCCT/EDIC genetics study. - Al-Kateb H; Mirea L; Xie X; Sun L; Liu M; Chen H; Bull SB; Boright AP; Paterson AD; DCCT/EDIC Research Group; Al-Kateb, Hussam; Mirea, Lucia; et al. (Diabetes, 2007)