Tat is produced very early upon infection [12–16] and continues to be expressed under cART [17, 18], is released extracellularly [19–21], accumulates in tissues [22, 23], and exerts effects on both the virus and the immune system [17, 24–52] that make it an optimal candidate for therapeutic immunization and cART intensification [53–58]. This evidence concerns the gene TAT and infection.