Since IPF is a fibroproliferative disease, and the level of proliferative capacity of activated fibroblasts may be increased in IPF patients [40], we sought to determine whether abnormal plakoglobin expression altered the proliferative response to PDGF or TGF-β in normal and IPF fibroblasts. The gene discussed is TGFB1; the disease is idiopathic pulmonary fibrosis.