FN1 and glomerulosclerosis: Glomerulosclerosis of the DN is the end point of a multifactorial mechanism leading to excess accumulation of extracellular matrix proteins, such as collagen types I, III, and IV and fibronectin in the mesangial space which, through the mesangial expansion stages and the Kimmelstiel-Wilson lesion development, results in glomerulosclerosis [3, 4].