Regarding DN, in streptozotocin (STZ)-induced DN models, mice lacking Smad3 were found to avoid renal fibrosis, including glomerular basement membrane (GBM) thickening and excessive extracellular matrix (ECM) production (Fujimoto et al., 2003), although the suppression of albuminuria was consistently observed (Wang et al., 2007). The gene discussed is SMAD3; the disease is renal fibrosis.