In the early stages of renal fibrosis, Bcl-3 protein levels were up-regulated prior to the up-regulation of HE4 protein levels (Figure 6A-6D), suggesting that although both Bcl-3 and HE4 protein levels in serum show strong positive correlations with renal fibrosis Bcl-3, as a potential biomarker, has a superior advantage and can serve as a biomarker for the diagnosis of renal fibrosis. The gene discussed is WFDC2; the disease is renal fibrosis.