[8] Moreover, activated T cells will also be easily targeted by the virus, thus contributing to progressive infection. Indeed, lower numbers of Treg have been associated with higher levels of immune activation in HIV-1 infection. [6], [27] Treg therefore seem to be maintaining a balance between persistent infection and decreased immune activation. As the CD4+ T cell population becomes depleted later in the disease, untreated patients would experience both increased immunosuppression and immune activation due to the eventual Treg depletion. Here, CD4 is linked to HIV-1 infection.