SCGB1A1 and pulmonary fibrosis: To further examine the role of PDCD5 in club cell-specific lung fibrosis, inducible Ccsp-TGFβ1-TG mice were bred to Ccsp-Pdcd5d/d mice to generate ablation of Pdcd5 and overexpression of TGF-β1 in the club cells (Supplementary Fig. 5b).