The killer immunoglobulin-like receptors (KIRs) on natural killer (NK) cells regulate the inhibition and activation of NK-cell responses through recognition of human leukocyte antigen (HLA) class I molecules. KIR3DL1, a receptor for HLA-B antigens with the Bw4 allele, transmits an inhibitory signal to prevent killer cell-mediated cytoxicity. KIR3DL1 encodes a 444 amino acid type I transmembrane protein, containing 3 immunoglobulin-like C2-type domains. Human KIR3DL1 maps to chromosome 19q13.4.
