Under ALI/ARDS conditions, lung epithelial cells communicate with immune cells by releasing EVs containing enzymes, including prolyl endopeptidase involved in the generation of the collagen-derived neutrophil chemoattractant Pro-Gly-Pro and caspase-3, which activates alveolar macrophages [113, 114]. The gene discussed is CASP3; the disease is acute respiratory distress syndrome.