To evaluate the role of NETosis in viral pneumonia, NETosis biomarkers were measured, incorporating citrullinated histone H3 (CitH3), myeloperoxidase (MPO), neutrophil elastase (NE), and LL-37 in the neutrophil from peripheral blood, as well as dsDNA and LL-37 in the serum of individuals suffering from viral pneumonia and healthy participants [13–15]. Here, MPO is linked to viral pneumonia.