In the current study, we have also shown that bleomycin treatment would downregulate the expression of the BMP4 gene which is consistent with the concurrent downregulation of the Dkk1 gene and previous data [35], although the treatment of the IPF mice with iPSCs did not affect restoring the expression of BMP4 gene. This evidence concerns the gene DKK1 and idiopathic pulmonary fibrosis.