FasL-expressing inflammatory cells have been identified in the bronchoalveolar lavage fluid and lung tissue of patients with idiopathic pulmonary fibrosis (IPF) and epithelial cells in IPF tissue were found to express Fas, suggesting that Fas/FasL interactions can promote ongoing alveolar epithelial cell death [18]. The gene discussed is FASLG; the disease is pulmonary fibrosis.