We demonstrated both in vitro and in vivo that although splenic CD8+ T cells exhibit an activated phenotype (CD44high), the sialoglycophenotype, modified by the action of Tc-TS activity, compromises the triggering of its cytotoxic activity, contributing to the increase of peripheral blood parasitemia (Freire-de-Lima et al., 2010). This evidence concerns the gene CD8A and parasitic infectious disease.