In a chronic (6 months) murine model for brucellosis it was reported that CD8+ T cells became nonfunctional or exhausted and could not express IFN-γ after stimulation with a purified MHC class I Brucella specific peptide when compared to CD8+ T cells prepared from spleens from acutely (2 weeks) infected mice [59]. The gene discussed is CD8A; the disease is brucellosis.