In both patients and animal models with DKD, there is a substantial increase in the expression or activation of TGF-β ligands, TGF-β receptors, and the subsequent signaling mediators like Smad2 and Smad3 in glomeruli, tubules, and the tubulointerstitium [46,198,199,200,201]. Here, TGFB1 is linked to diabetic kidney disease.