Receptor on natural killer (NK) cells for some HLA-C alleles such as w4 and w6. Inhibits the activity of NK cells thus preventing cell lysis. Interacts with ARRB2. Interacts with PTPN6; the interaction is enhanced by ARRB2. Interacts with PTPN11; the interaction is enhanced by ARRB2. Expressed by NK cells. Belongs to the immunoglobulin superfamily.