On day 17 post infection (7 days after the beginning of Treg depletion), the effector T cell response was analyzed, and despite the re-emerging Treg population in DEREG mice (Figure 1d), a slight increase in the frequency of IFN-γ+ and TNF-α+ CD8+ and CD4+ effector T cells could be observed following Treg depletion (Figure 1e,f). This evidence concerns the gene CD4 and infection.