Also, it is widely believed that most HIV-specific CD4 T-cells, which should represent the bulk of activated CD4 T-cells during PHI, are lost, presumably due to infection, unless patients commence cART (Rosenberg et al., 1997), consistent with the report that HIV-specific CD4 T-cells are preferentially infected with HIV DNA (Douek et al., 2002). Here, CD4 is linked to infection.