Thus, while the infection of LysM-Stat1−/− mice is associated with reduced iNOS and nitrate production, the uncontrolled parasite replication in the small intestines of these mice also formally establishes the importance of the IFN-γ-dependent, STAT1-mediated antimicrobial effector functions in macrophages for the control of T. gondiiin vivo. This evidence concerns the gene NOS2 and infection.