FASN and idiopathic pulmonary fibrosis: The results revealed co-localization of FASN and α-smooth muscle actin (α-SMA)–positive fibroblasts in the fibrotic lesions of IPF, whereas FASN was predominantly expressed in type II alveolar epithelial cells in the donor lungs, and no significant co-localization of α-SMA and FASN was observed (Fig 1A).