Also, bone marrow-associated CD4+ T cell proliferation during chronic infection has shown to be important for maintenance of stable CD4+ T cell counts in SMs,58 while lower rates of infection in crucial CD4+ T cell subsets with high proliferative potential, such as stem cell memory (Tscm) and Tcm, have been described as a distinctive feature of natural SIV hosts that may also contribute to preserve intact CD4+ T cell homeostasis.59 This evidence concerns the gene CD4 and infection.