FN1 and renal fibrosis: Renal ECM is a non-cellular three-dimensional macromolecular network composed of various glycoproteins such as collagen, elastin, proteoglycan and fibronectin, of which type I and type III collagen and fibronectin play a major role in renal fibrosis, and these proteins play an important role in the process of renal fibrosis under the regulation of integrins and their downstream signals [16, 17].