SHH and idiopathic pulmonary fibrosis: IPF is characterized by the reactivation of developmental pathways (SHH, Wnt, Notch and TGF-β) and downstream TFs [ETV (ETV4/5), β-catenin, GLI and SMADs, respectively] (Chilosi et al., 2003; Cigna et al., 2012; Froidure et al., 2020; Zhang et al., 2017; Zhao et al., 2002).