Predominant p21 induction in tubular cells by high glucose (HG) was confirmed in vitro comparing mouse primary tubular cells (PTCs), mesangial cells (MESs), glomerular endothelial cells (GECs), and podocytes (Pod, Fig. 2d) and in diabetic eNOS−/− mice, an established murine model with severe DKD (Supplementary Fig. 3c, d). Here, CDKN1A is linked to diabetic kidney disease.