In addition, future studies of gut CD8+ T cell differentiation and senescence in the context of chronic HIV infection could be informative in determining whether HIV induced severe disruption of gut homeostasis [69, 70], including severe depletion of resident Th17 CD4+ cell populations [71, 72] and chronic activation of resident CD8+ T cells [5, 73], could disrupt gut homeostasis and cause an increase in senescent/dysfunctional features on resident CD8+ T cells. This evidence concerns the gene CD4 and HIV infectious disease.