We treated primary human lung fibroblasts from IPF patients (IPF fibroblasts, IPFFs) with conditioned media (CM) from ATII cells transfected with control or ATG5 siRNA (Fig. 5a) without or with addition of transforming growth factor-β (TGF-β), and assessed levels of α-smooth muscle actin (α-SMA), a marker of myofibroblast differentiation. Here, ATG5 is linked to idiopathic pulmonary fibrosis.