IFNG and ocular toxoplasmosis: In chronic asymptomatic individuals, the PBMCs' immune responses against total lysate antigen and against peptides derived from T. gondii are predominantly characterized by high levels of interferon gamma (IFN-γ) (Prigione et al., 2006; Bayram Delibaş et al., 2009; Cong et al., 2011; Cardona et al., 2015; Meira et al., 2015); in ocular toxoplasmosis and Toxoplasma-seronegative individuals, however, the level of this cytokine is much lower (Alfonzo et al., 2005; Meira et al., 2014; Maia et al., 2017).