MPO and acute respiratory distress syndrome: To assess context in ARDS pathogenesis, we studied biomarkers of pathogenic events in ARDS relevant to neutrophil-mediated secondary tissue injury: interleukin-6 (IL-6 marker of cytokine storms), soluble C5b9 (terminal complex of complement activation), myeloperoxidase or MPO (neutrophil activation), ratio of the number of copies of mitochondrial to nuclear DNA in plasma (mtDNA-NET-formation)24, and DEspR+CD11b+ cytoplasts, (anuclear remnants of neutrophils associated with “vital NETosis”)25.