TNF and acute respiratory distress syndrome: At early stages of acute lung injury and ARDS, alveolar macrophages initiate pro-inflammatory signaling through the release of TNF, IL-1β and other cytokines that propagates the innate immune response and inflammation and potentiates chemokine secretion to recruit neutrophils, exudative macrophages, and lymphocytes (Herold et al., 2011; Aggarwal et al., 2014).