FAS and acute respiratory distress syndrome: We have also found that sFasL is present in the bronchoalveolar lavage (BAL) fluid of patients with ARDS, that administration of sFasL to mice and rabbits results in lung injury, and that mice lacking Fas have attenuated alveolar inflammation in response to intratracheal lipopolysaccharide (LPS), mechanical ventilation, or viral infection [6, 9–11, 17].