IL18 and acute respiratory distress syndrome: We have demonstrated that (1) Casp1−/− mice in our ALI model were rescued from developing hypoxemia along with significantly low amounts of IL-18 as well as IL-1β in BAL (Figures S5A,B); (2) a high volume ventilation (HVV) “single-hit” model can also produce equal amounts of IL-18 as the LPS plus HVV “two-hit” model (Figures S5C,D), while the production of IL-1β requires the two-hit (12).