The heightened inflammatory response was not associated with a paucity of regulatory T cells: similar numbers, and frequency within the CD4 compartment, of Foxp3+ regulatory T cells were found at the infection site of CCL7 KO and WT mice (mean/SEM number/ear: WT 45.46 ± 11.7, CCL7 KO 48.54 ± 17.03). This evidence concerns the gene CD4 and infection.