However, with regard to the reduced frequency of activated CD4+Ly6Chi T effector cells, the lesion area was larger in the Pdl1−/− mice compared to the WT mice early after infection (12 dpi) (Figure 6A), although a similar number of parasites was observed in the two mouse strains at each time point analyzed (12, 18, 35 dpi) for both the ear (Figure 6A) and the dLN (Figure 6B). Here, CD4 is linked to infection.