Tang et al.52 demonstrated that renin levels are greater in the urine of both patients with diabetes and mice with induced diabetes type I. To examine the role of filtration and tubular reabsorption on urinary renin, the authors used mice infused with recombinant renin and lysine, which is an inhibitor of proximal tubular protein reabsorption. This evidence concerns the gene REN and type 1 diabetes mellitus.