Using TNF or TNFRs-deficient mice, it has been demonstrated that they are essential for survival of infections with bacterial pathogens such as Listeria monocytogens, Mycobacterium tuberculosis, M. avium, Salmonella typhimurium, intracellular parasites such as Leishmania major or Trypanosoma cruzi, and viruses such as herpes simplex virus (HSV-1), mouse cytomegalovirus (MCMV), or lymphocytic choriomeningitis virus (LCMV)[2,4,13]. This evidence concerns the gene TNF and infection.