The ligand for KIR3DS1 has not been determined, although it has been shown that the KIR3DS1 activating receptor in combination with HLA-B alleles that encode molecules with isoleucine at position 80 (HLA-B Bw4-I80) results in delayed progression to AIDS after HIV-1 infection [10]. The gene discussed is HLA-B; the disease is HIV-1 infection.