14,15 Even though the exact mechanism(s) of polyfunctional T cell mediated protection are still not clear, it has been shown that two or more cytokines can work synergistically to control infection, as in the case of a closely related mycobacterium, M. tuberculosis58 and Leishmania spp.59 Indeed, PAN-Cf vaccinated (prechallenged) mice exhibited polyfunctional CD8+ T cells (IFN-γ+, IL-2+, TNFα+) but showed superior protection (significantly lower bacterial burden) compared with both non-vaccinated (all organs) and Mycopar (only spleen) vaccinated groups. This evidence concerns the gene TNF and infection.