As shown in Fig. 6, compared with IFN-γ stimulation alone, TNF-α (10 ng/ml) and IFN-γ (10 ng/ml) combination induced significantly higher iNOS mRNA expression (Fig. 6A and 6B) at 36 h after Cm infection, in parallel with increased inhibition of Cm growth (Fig. 6C). Here, TNF is linked to infection.