In L-MSCs cultured from donors with both non-IPF and IPF, transforming growth factor beta (TGF-β1) induces expression of profibrotic mediators, plasminogen activator inhibitor 1 (PAI-1) and collagen type 1 alpha 1 (COL1A1). This evidence concerns the gene TGFB1 and idiopathic pulmonary fibrosis.