Furthermore, Fang et al. (2018) demonstrated that p38 MAPK is essential for the epithelial–mesenchymal transition of AECs induced by Wnt1 and lithium chloride, and Antoniou et al. (2010) proposed the involvement of the MAPK signaling pathway in IPF pathogenesis. Here, WNT1 is linked to idiopathic pulmonary fibrosis.