In particular, DKK1 expression in the renal tissues of the 5/6 Nx rats was strongly correlated with renal fibrosis (Figure 2 and Figure 3), and the knockdown of DKK1 by DKK1-AS remarkably attenuated the CKD-associated phenotypes (Figure 2 and Figure 3). The gene discussed is DKK1; the disease is renal fibrosis.