MPO and infection: Fusion of phagosomes with azurophilic granules containing myeloperoxidase (MPO) has been described during infection of human neutrophils in vitro with L. major and L. donovani (49), however, little is known about the phagolysosome biology of neutrophils during Leishmania infection and an important question that remains to be elucidated is if the differences in phagolysosome maturation influences promastigote-amastigote differentiation in different phagocytic cells and how this might impact the development of disease.