Renin-angiotensin-aldosterone system (RAAS), advanced glycation end product (AGE) formation, activation of transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), protein kinase C (PKC), mitogen-activated protein kinase (MAPKs), and reactive oxygen species (ROS) are important pathways to the development and progression of DN. This evidence concerns the gene CCN2 and liver dysplastic nodule.