Many studies demonstrate the role of COX-2 and PGE2 during infections triggered by pathogens (Michelin et al., 2005; Abdalla et al., 2008; Tatakihara et al., 2008; Moraes et al., 2015), however there are no studies demonstrating association between COX-2 and susceptibility to T. gondii infection. This evidence concerns the gene PTGS2 and infection.