IFNG and infection: The role of interferon-gamma (IFN-γ) was initially examined in E. vermiformis infected BALB/c mice, where blocking of endogenous IFN-γ by an IFN-γ specific monoclonal antibody in-vivo resulted in increased susceptibility to primary but not secondary infection, and increased oocyst production during primary infection compared with mice not injected with the antibody (67).