TGFB1 and pulmonary fibrosis: To explore the pathogenic significance of autocrine TGF-β signaling in fibrosis, we generated an AT2-specific Tgfbr2 conditional knockout mouse line, SftpcCreERT2; Tgfbr2flox/flox (hereafter Tgfbr2-cKO), to disturb TGF-β signaling in AT2-lineage cells and prepared a BLM-induced lung fibrosis model.