FN1 and idiopathic pulmonary fibrosis: In addition, we demonstrate that treatment of primary IPF fibroblasts with a TG2-selective inhibitor 1–155 and a cell impermeable TG2 inhibitor R281 reverses the myofibroblast phenotype with reduced expression of FN, TG2 and αSMA and reduced deposition into the ECM of TG2, FN and TGFβ1.