Many studies demonstrated the important protective role of IFN-γ, nitrite (Gazzinelli et al., 1994; Lang et al., 2007; Kemp et al., 2013; Koblansky et al., 2013; Behnke et al., 2017; Abreu-Cabral et al., 2018), IL-17A (Kelly et al., 2005), MIF (Ferro et al., 2008; Flores et al., 2008; Terrazas et al., 2010; Gomes et al., 2011, 2018; Barbosa et al., 2014), TNF and IL-6 (Castro et al., 2013; Barbosa et al., 2014, 2015) during infection by T. gondii. This evidence concerns the gene IL6 and infection.