GREM1 and pulmonary fibrosis: The anti-fibrotic agent pirfenidone is used to treat idiopathic pulmonary fibrosis and may be useful as adjuvant therapy for mesothelioma, due to its ability to stimulate the BMP pathway while impairing AKT/mTOR signaling, non-canonical Akt and Erk dependent TGFβ signaling, and expression of the BMP antagonist gremlin-1 (GREM1) [108].