Overall, although a beneficial effect of KIR3DS1 in the context of HIV-1 infection has been observed in some in vivo and in vitro, it remains unknown whether this effect is mediated by KIR3DS1 itself or other genes in linkage disequilibrium with KIR3DS1. Furthermore, it is not clear whether changes in KIR3DL1 copy numbers in KIR3DS1+ individuals are responsible for this protective effect or whether this is dependent on the simultaneous presence of HLA-Bw4-I80. The gene discussed is KIR3DL1; the disease is HIV-1 infection.