TGFB1 and idiopathic pulmonary fibrosis: As proof of principle, we generated a model of the progressive scarring observed in IPF by treating fetal lung fibroblast organoids or induced pluripotent stem cell‐derived mesenchymal cell organoids with exogenous transforming growth factor‐β1 (TGF‐β1) and showed that there is a progressive scarring phenotype in the dish that resembles IPF.