Receptor on natural killer (NK) cells and T cells for MHC class I molecules (PubMed:24018270, PubMed:28636952). Upon binding of peptide-free HLA-F open conformer, negatively regulates NK and T cell effector functions (PubMed:24018270). Acts as a receptor on astrocytes for HLA-F. Through interaction with HLA-F, may protect motor neurons from astrocyte-induced toxicity (PubMed:26928464). Interacts with peptide-free HLA-F open conformer. Expressed in astrocytes. Belongs to the immunoglobulin superfamily.