In support of this hypothesis, in vitro production of PGE2 by spleen cells harvested from mice at 12 dpi did not change between animals inoculated with PBS or EV Y prior to infection, while the pro-inflammatory cytokines were downregulated in the same cells from animals inoculated with EV Y. Moreover, Moraes et al. showed that during the first 48 h of T. cruzi infection in H9c2 cells, COX-2 expression and activity are modulated by the parasite, leading to the control of the pro-inflammatory environment in infected cells (81). This evidence concerns the gene PTGS2 and infection.