Thus, aberrant DNA methylation and concurrent upregulation of Tgfb1 mRNA reported here were observed in mesangial cells specifically, demonstrating the important role of mesangial cell-specific DNA demethylation in upregulation of Tgfb1 mRNA expression and subsequent mesangial fibrosis and matrix expansion in DN. The gene discussed is TGFB1; the disease is liver dysplastic nodule.