APOE and liver dysplastic nodule: Tumor growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) play an important role in the pathogenesis of DN which confined to extracellular proteoglycans, suggesting that ApoE may regulate the levels and biological activity of TGF-β and PDGF in the extracellular matrix and thereby affecting renal effects of DN.