To further address the role of TNF for the innate and adaptive response to L. major and to reconcile previous discrepant results obtained with TNF- or TNF-receptor-deficient mouse strains of different genetic origins (Vieira et al., 1996; Nashleanas et al., 1998; Chakour et al., 2003), we infected mice deficient for membrane and soluble TNF (Tnf-/-), for soluble TNF alone (memTnfΔ/Δ), for TNF receptor type 1 (Tnfr1-/-), or type 2 (Tnfr2-/-) on a pure C57BL/6 background to comprehensively assess the course of leishmaniasis. Here, TNF is linked to leishmaniasis.