To examine the effect of sRAGE on UUO-induced tubulointerstitial fibrosis and macrophage accumulation, we analyzed the changes in fibronectin, type I collagen, α-SMA, and ED-1 protein expression using Western blot and IHC staining and assessed tubulointerstitial fibrosis by Masson’s trichrome staining. The gene discussed is FN1; the disease is fibrosis.