Given the importance of ROS overproduction in diabetic glomerular injury and mesangial fibrosis through TGFB1 upregulation16,28,29, even delayed treatment with Tempol could decrease Tgfb1 mRNA, inhibit mesangial cell fibrosis, and decrease albuminuria in diabetic rodents30,31. This evidence concerns the gene TGFB1 and fibrosis.