FAP and idiopathic pulmonary fibrosis: In addition, FAP expressed by pre-adipocytes has been shown to regulate signals such as the mammalian target of rapamycin (mTOR) by mediating ECM remodeling and to alter lipid metabolism (80), while FAP-mTOR-related signaling has been shown to alter collagen deposition in idiopathic pulmonary fibrosis (IPF) (81).