MPO and infection: In addition, neutrophils may release extracellular chromatin fibers with elastase, cathepsin G, lactoferrin, gelatinase, and myeloperoxidase (MPO) from neutrophilic granules neutrophil extracellular traps (NETs) after infection by pathogens, parasites, and viruses (Brinkmann et al., 2004; Galluzzi et al., 2018).