TGF-β1, a known pro-fibrotic factor, activates the production of extracellular matrix by mesangial cells and interstitial fibroblasts in the kidneys, and thus contributes to the manifestation of diabetic kidney disease through a number of key pathological events leading to reduced glomerular filtration and impaired renal function [39,40]. This evidence concerns the gene TGFB1 and diabetic kidney disease.