In an experimental study, T. lewisi infection increased the susceptibility of Sprague–Dawley rats to T. gondii infection, and this phenomenon was associated with the reduction in the production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in peritoneal macrophages (28), important molecules for the control of T. gondii infection (29), favoring its dissemination in the host, showing that in situations of coinfection, the presence of a pathogen can favor infection by another pathogen. The gene discussed is NOS2; the disease is infection.