Editor, I read the recent report on IL-2 and IFN-gamma study on rat model with great interest [1]. Johnsen-Soriano et al. concluded that “Immunoregulatory cytokines belonging to the Th-1 group (IL-2 and IFN-gamma) were increased in the retina of experimental diabetic rats [1]” and “the nitrotyrosine formation (as an expression of increased NO production) was significantly elevated in the diabetic retina, supporting the concept of an inflammatory element in the development of diabetic retinopathy [1].” I have some comments on this work. Whether the experimental design is statistically acceptable should be discussed. The exact process that induced the increasing IL-2, IFN-gamma and NO production in the experimented rats is still questionable . Indeed, evidence of no oxidation flux change in retina membrane is reported [2]. The concern on diabetic retinopathy is not limited to the hyperglycemic stage but the control of fluctuation of the blood glucose. An important cause of cellular damage in diabetes is the exothermic energy from fluctuation of blood glucose [3].