Furthermore, the in vivo blockade of NO production in T. cruzi infected animals, by injection of the inducible NO synthase (iNOS) inhibitor aminoguanidine (AG) in the early phase of acute infection, brought the parasitemia and mortality of treated WT mice to the same levels obtained in treated Tlr4−/− animals (Figure 5C and D). Here, TLR4 is linked to parasitic infectious disease.