FN1 and idiopathic pulmonary fibrosis: In recent studies, AMPK activators such as metformin, have shown a protective effect against IPF by preventing the TGF-β/Smad signalling pathway and release of collagen, fibronectin, α-smooth muscle actin (α-SMA), and other fibrogenic factors (Rangarajan et al. 2018; Cheng et al. 2021; Wu et al. 2022).