To confirm this, we then analyzed several known clock-controlled genes for the retina (Storch et al., 2007; Vancura et al., 2021) (Adcy1, Drd4, Nr2e3, Cys1, Plekbh1, Usp2) (S. Fig. 2) that also showed amplitude changes but no phase changes, indicating that the retinal clock was entrained to the 12L:12D cycle at this stage of diabetes. This evidence concerns the gene DRD4 and diabetes mellitus.