In both animal and human models, the TGF-β/Smad 2/Smad 3 signaling pathway has been described as playing a crucial role in regulating DN progression by stimulating the production of ECM components such as collagen I, IV, laminin, fibronectin, as well as fibroblast proliferation and epithelial–mesenchymal transition [110,111]. Here, TGFB1 is linked to liver dysplastic nodule.