Wilkinson et al. (2017b) generated a model of progressive scarring that resembled human IPF by treating fetal lung fibroblast organoids or inducing pluripotent stem cell-derived mesenchymal cell organoids with TGF-β. In another example, bleomycin treatment induced IPF phenotypes such as fibroblast activation, cellular senescence and morphological change in human PSC-derived alveolar organoids (Suezawa et al., 2021). This evidence concerns the gene TGFB1 and idiopathic pulmonary fibrosis.