FASLG and idiopathic pulmonary fibrosis: Methods. We analyzed, by immunohistochemistry, the expression of the apoptotic markers fas, fas ligand , bcl-2, and bax in AM obtained from bronchoalveolar lavage fluid (BALF) of 20 newly diagnosed, treatment-naive IPF patients and of 16 controls.Apoptosis of AM was evaluated by Apoptag immunohistochemistry.