On the other hand, the molecular mechanisms that allow the activation of monocytes/macrophages and the synthesis and release of inflammatory cytokines are less well characterized, even if we and others reported that in macrophages Nef is able to activate NF-κB signalling pathways and that this activation is responsible for the production of cytokines and for the increased infection of resting T lymphocytes [12], [14]. This evidence concerns the gene S100B and infection.