Persistent M1 macrophage activation leads to excessive release of inflammatory cytokines, such as interferon γ (IFN-γ), tumor necrosis factor (TNF; previously known as TNF-α), interleukin 1 (IL-1β), and nitric oxide (NO), which is believed to contribute the most to the pathogenesis of ALI.8 Here, IFNG is linked to acute respiratory distress syndrome.