On the other hand, Travi et al. [11] observed that the PMBC stimulated with SLA from 67% of symptomatic dogs experimentally infected with promastigotes isolated from the vector Lutzomyia longipalpis produced high levels of IFN-γ at the early stages of infection, and the proportion of individuals producing this cytokine increased over time, indicating that IFN-γ production and expression was not sufficient to prevent disease and, consequently, was not a good marker of resistance. This evidence concerns the gene IFNG and infection.