Anti-CR2 antibodies are used in the immunodetection of the protein complement C3d receptor 2. In humans, the canonical protein has a reported length of 1033 amino acid residues and a mass of 112.9 kDa. Its subcellular localization is in the cell membrane. Up to 4 different isoforms have been reported for this protein. It is notably expressed in the tonsil, spleen, lymph node, and appendix. A member of the Receptors of complement activation (RCA) protein family, Cr2 is a known receptor for complement C3, for the Epstein-Barr virus on human B-cells and T-cells and for HNRNPU. Post-translational modifications have been described, including glycosylation. The CR2 marker can be used to identify Large Intestine Lamina Propria Lymphocytes, Follicular Dendritic Cells, and Follicular Dendritic Cells (FDC).* Synonyms for this target antigen include CD21, CR, CVID7, SLEB9, complement receptor type 2, and C3DR. CR2 gene orthologs have been reported in the mouse, rat and bovine species.
*HuBMAP Human Reference Atlas v1.4