TGFB1 and fibrosis: Overproduction of ROS in the kidney can induce diabetic glomerular injury and mesangial fibrosis through TGFB1 upregulation in DN27–29; however, treatment with Tempol, a superoxide dismutase (SOD) mimetic, can decrease Tgfb1 mRNA, inhibit mesangial cell fibrosis, and decrease albuminuria in diabetic rodents30,31.