In addition, in untreated HIV-infected patients, as well as Simian Immune deficiency virus (SIV)-infected macaques, HIV/SIV-specific CD8+ T-cells exhibit a high cytotoxic potential (namely, high expression of perforin and granzyme B) in early infection, but this capacity decreases during chronic infection [58–60]. The gene discussed is PRF1; the disease is infection.