TNF and acute respiratory distress syndrome: In the mouse ALI model, exosomes secreted by alveolar macrophages were found to carry TNF and IL-1β into alveolar epithelial and endothelial cells, promoting the expression of cell adhesion molecule ICAM-1, the injury of endothelial cells, and the infiltration of polymorphonuclear leukocytes (PMN) in the lung and mediating the lung inflammatory injury of ALI (Ye et al., 2020).