CD4:CD8 ratio and HIV infection: The 'tap-and-drain' hypothesis

The balance of CD4(+) and CD8(+) T cells in humans is controlled by a major autosomal gene. Here, Alberto Amadori and colleagues propose that in view of the high CD4(+) cell turnover during HIV infection, individuals genetically predisposed to a high CD4:CD8 ratio can withstand HIV-associated CD4(+) cell losses better than those predisposed to a low ratio.