HIF1A and non-proliferative diabetic retinopathy: Despite the preserved sensitivity to the destabilizing effect of hyperglycemia (Figure 2(b)), the transactivation activity of HIF-1α Pro582Ser is increased even in high glucose concentration (Figure 2(c)), which might explain the protective effect of the HIF-1A Pro582Ser polymorphism for the risk for severe NPDR/PDR.