IFNG and infection: In mouse model of L. major infection, the type of T-cell response determines the outcome of the infection; in resistant mice, a Th1 response is induced with production of IFN-γ, the lesion cure and the animals are protected against challenge, which is somehow similar to human CL, while in susceptible BALB/c mice, Th2 response is generated and a high level of IL-4 is produced, IFN-γ production is down regulated, and every infected mouse is succumbed to the disease.