SMAD3 and pulmonary fibrosis: In patients with idiopathic pulmonary fibrosis and mice with bleomycin-induced pulmonary fibrosis, AEBP1 expression is upregulated in lung tissue [19], where it controls myofibroblast differentiation through a mechanism involving activation of transforming growth factor beta receptors, stimulation of SMAD3, enhanced expression of smooth muscle actin, and subsequent collagen production [19].