Nef affects the function of macrophages inducing the production of two CC-chemokines, (i.e. CCL3/MIP-1 and CCL4/MIP-1β) possibly to recruit CD4+ T cells at the sites of virus replication, and induces the release of soluble factors from macrophages (i.e. sICAM-1 and sCD23) stimulating B cells to render resting T lymphocytes more permissive to HIV-1 infection and replication [11], [12]. This evidence concerns the gene S100B and HIV-1 infection.