NOX4 and fibrosis: After 4-weeks of diabetes, diabetic Hhip+/+ animals had evidence of renal hypertrophy (Fig. 6b), increased GFR (Fig. 6c) and urinary ACR (Fig. 6d), and developed DN features (Fig. 6e) including glomerulosclerosis, glomerular fibrosis and podocyte loss (co-IF staining with p57 and Hhip), as well as elevated oxidative stress (Nox4-IHC).