The latent reservoir is established immediately following infection, as early as 3 dpi, and prior to detectable viremia [28,29,30,331], in resting CD4+ T cells: [303,304,332,333,334,335] with different immunophenotypes: central memory [312,335,336], transitional memory [312,336], stem cell memory T cells [337], Tregs [338], and follicular T helper CD4+ cells [339]. This evidence concerns the gene CD4 and infection.