Hou et al. found that Shh-producing AT2 cells boosted macrophage M2 polarization and bleomycin-induced pulmonary fibrosis progression via the Shh/GLI1/OPN/Janus kinase (JAK) 2/signal transducer and activator of transcription (STAT) 3 cascade [107]. This evidence concerns the gene GLI1 and pulmonary fibrosis.