Thirdly, the correlation between serum CN-1 concentration and urinary protein components in our study was not only found in glomerular damage biomarkers (i.e., macromolecular Alb, IgG, TRF and micromolecular Cys-C) but also in tubular damage biomarkers (i.e., NAG, RBP, α1-MG and β2-MG), which suggested serum CN-1 could also be a surrogate for DN. This evidence concerns the gene CNDP1 and liver dysplastic nodule.