The injury of mesangial cells and podocytes caused by diabetic nephropathy can activate the signal transduction cascade of the TGF-β/Smad signaling pathway and stimulate the expression of TGF-1, TSP-1, and TGF-IIR in GEC, thus activating the Smad signaling pathway and leading to increased production of ECM (Kim et al., 2003). This evidence concerns the gene TGFB1 and diabetic kidney disease.