Anti-Calcium-Sensing Receptor antibodies are used in the immunodetection of the protein encoded by the CASR gene. In humans, the canonical protein has a reported length of 1078 amino acid residues and a mass of 120.7 kDa. Its subcellular localization is in the cell membrane. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be expressed in the temporal lobe, frontal lobe, parietal lobe, hippocampus, and cerebellum. A member of the G-protein coupled receptor 3 protein family, it is reported to be a G-protein-coupled receptor that senses changes in the extracellular concentration of calcium ions and plays a key role in maintaining calcium homeostasis. Post-translational modifications have been described, including N-glycosylation, ubiquitination. Other names for this target antigen include EIG8, FHH, FIH, GPRC2A, HHC, HHC1, HYPOC1, and CAR.