ENPP1 and infection: Though this awaits further validation, the peroxidase/catalases, peroxide reductases, and the NPP1 homolog expressed in the pathogen during late stages of infection may reflect the mounting effort on the part of the pathogen to combat high levels of certain reactive oxygen species produced by the plant, and also to inflict cell death at the late stage of infection when symptoms including both chlorosis and necrosis may be present.