Improved understanding of pathogenesis in acute lung injury (ALI) has led to discovery of novel therapeutic targets such as pro-inflammatory cytokines 1, 2, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and reactive oxygen species (ROS) 3, which are all secreted by M1-type alveolar macrophages. Here, TNF is linked to acute respiratory distress syndrome.