Figure 5A shows that NO production was significantly increased in the cells treated with LPS+IFN-γ but decreased in the macrophages treated with L-NAME. We further demonstrate that the number of T. gondii/100 cells was significantly decreased in the macrophages treated with LPS+IFN-γ but significantly increased in those treated with L-NAME (p<0.05) at 24 hrs after infection (Figure 5B). The profile of the ratio of infected cells to uninfected cells showed a similar significant pattern (Figure 5C). This evidence concerns the gene IFNG and infection.