TNF and acute respiratory distress syndrome: The activation of macrophages initiates the inflammatory response in LPS-induced ALI by releasing proinflammatory cytokines (tumor necrosis factor-alpha (TNF-α)), interleukin ((IL)-1β and IL-6), anti-inflammatory cytokines (IL-4 and IL-10), and proinflammatory mediator (NO) that are related to the tissue-injury sites in immune cell recruitment [5].