However, IFN-γ−/− C57BL/6 mice are as susceptible to L. amazonensis infection as the wild-type mice, at least for the first 2 months of infection, but they have more severe disease afterward (in the absence of an IL-4 dominance) (Pinheiro and Rossi-Bergmann, 2007). The gene discussed is IFNG; the disease is infection.