The proportions of MPO-positive mice varied across infection with no difference at 4 days PI, decreased MPO detection in Mcpt4-/- versus Mcpt4+/+ mice at 6 days PI, low MPO detection in Mcpt4-/- mice relative to no detection in Mcpt4+/+ mice at 8 days PI and decreased MPO detection in Mcpt4-/- versus Mcpt4+/+ mice at 10 days PI (Figure 4A). Here, MPO is linked to infection.