BMP4 and idiopathic pulmonary fibrosis: Characterization of LR-MSCs from the BAL fluid of patients with stable and progressive IPF have identified differential expression patterns in genes that regulate lung development, including FGF-10 and BMP-4.67 These findings highlight the suppression of the epithelial mitogen FGF-10 in progressive IPF and identified TGF-β and sonic hedgehog protein (SHH) signaling as critical mediators of this effect in LR-MSCs.