Hu et al. found that intravitreal injections of VEGF caused a significant reduction of scotopic ERG a-wave and b-wave amplitudes and photopic ERG b-wave amplitudes, in a dose-dependent manner. Thus, VEGF appears to be a direct functional regulator of photoreceptors, and its up-regulation in DR contributes to diabetes-induced alteration of photoreceptor function [12]. The gene discussed is VEGFA; the disease is diabetes mellitus.