TGF-β1 plays a major role in the pathogenesis of IPF; therefore, both cell types were treated with human recombinant TGF-β1 (5 ng/mL) for 24 h, which significantly increased hypertrophy and the fusion of mitochondria in control and IPF cells (Figure 1C). Here, TGFB1 is linked to idiopathic pulmonary fibrosis.