<prompt> Neutrophils secreteSuperoxide dismutaseMyeloperoxidaseLysosomal enzymeCatalase  <response>: Ref Robbins 9e p 73 Myeloperoxidase MPO is a peroxidase enzyme that in humans is encoded by the MPO gene on chromosome 17. MPO is most abundantly expressed in neutrophil granulocytes a subtype of white blood cells, and produces hypohalous acids to carry out their antimicrobial activity. It is a lysosomal protein stored in azurophilic granules of the neutrophil and released into the extracellular space during degranulation. Neutrophil myeloperoxidase has a heme pigment, which causes its green color in secretions rich in neutrophils, such as pus and some forms of mucus. The green color contributed to its outdated name verdoperoxidase 