Previous studies have implicated this KIR-HLA combination in both HIV-1 disease progression [17], [19] and risk of HIV-1 infection [13] and interestingly it is the combination of high expressing KIR3DL1 alleles as well as the cell-retained receptor expressed by the KIR3DL1*004 allele, in combination with Bw480Ile (often the HLA-B*57 allele) that confer a strong protective effect. Here, HLA-B is linked to HIV-1 infection.