DKK1 and idiopathic pulmonary fibrosis: We also assessed the expression of Wnt signaling pathway genes (Wnt, β-catenin, Lef, and Dkk1); it was subsequently found that Wnt, β-catenin, and Lef genes were upregulated while Dkk1 was downregulated in the bleomycin-induced IPF model and iPSCs treatment normalized their expression.