KIR3DL1 and AIDS: In the case of HIV-1, activating and highly-expressed inhibitory alleles of KIR3DL1/S1, in combination with HLA-Bw4 alleles encoding isoleucine at position 80 (HLA-Bw4-80I), are associated with delayed progression to AIDS and greater suppression of viral replication in autologous CD4+ T cells by bulk NK cells [8,9,16].