While no changes in tissue integrity were observed after 1 week of infection in both groups (Fig 2A1–2A3 and 2B1–2B3), the two IFNγ-/- mice displayed massive oedema formation and tissue necrosis after 5 weeks of infection (Fig 2B5, 2B4 and 2B6, respectively). This evidence concerns the gene IFNG and infection.