In this study, we showed that N. caninum injection increased infiltration of CD8+ T cells and macrophages into the tumor, along with increased expression of IL-12, IFN-γ, IL-10, TNF-α, and IL-2 mRNA, which can also be induced by N. caninum in a mouse model, as reported in other studies [21, 24]. This evidence concerns the gene TNF and neoplasm.