In a recent study, we demonstrated that REDD1 protein expression is increased in the retina of diabetic mice, and deletion of REDD1 is sufficient to prevent diabetes-induced retinal cell death, electroretinogram (ERG) defects, and impaired visual thresholds.22 The protective effect of REDD1 deletion on diabetes-induced deficits is consistent with functional expression of REDD1 in the inner retina. This evidence concerns the gene DDIT4 and diabetes mellitus.