Immune activating receptor involved in self-nonself discrimination. In complex with KLRD1 on cytotoxic lymphocyte subsets, recognizes non-classical major histocompatibility (MHC) class Ib HLA-E loaded with signal sequence-derived peptides from non-classical MHC class Ib HLA-G molecules, likely playing a role in the generation and effector functions of adaptive natural killer (NK) cells and in maternal-fetal tolerance during pregnancy (PubMed:9754572, PubMed:30134159). Regulates the effector functions of terminally differentiated cytotoxic lymphocyte subsets, and in particular may play a role in adaptive NK cell response to viral infection (PubMed:21825173, PubMed:20952657). Upon HLA-E-peptide binding, transmits intracellular signals via the adapter protein TYROBP/DAP12, triggering the phosphorylation of proximal signaling molecules and cell activation (PubMed:9655483, PubMed:15940674). Heterodimer with KLRD1; disulfide-linked. KLRD1-KLRC2 receptor complex interacts with TYROBP homodimer; this interaction is necessary for the expression on the cell surface (PubMed:20890284, PubMed:9655483). KLRD1-KLRC2 receptor complex can bind with low affinity to HLA-E loaded with self-peptides derived from the signal sequence of classical MHC class Ia (PubMed:18083576, PubMed:9486650). Expressed in NK cell subsets, in particular in adaptive CD57-positive NK cells (at protein level) (PubMed:20952657, PubMed:21825173). Expressed in terminally differentiated cytotoxic gamma-delta T cells (at protein level) (PubMed:20952657). Expressed in alpha-beta T cells subsets (at protein level) (PubMed:20952657). KLRD1-KLRC1 and KLRD1-KLRC2 are differentially expressed within NK and T cell populations, with only minor subsets expressing both receptor complexes (at protein level) (PubMed:20952657). Two alleles are known. The sequence shown is that of allele NKG2-C*01.