Telomere length analysis could be helpful in determining if exhaustion and replicative senescence are involved in HIV-1 pathogenesis. Evidence that CD8+ T cells have shorter telomeres may point towards an increased turnover of CD8+ T cells and exhaustion of the CD8+ T-cell responses in HIV-1 infection. In CD4+ T cells, the relationship between telomere length and turnover remains controversial; however, telomere length analysis argues against exhaustion of CD4+ T cells.