Anti-B220 antibodies are protein reagents that detect specific antigens. The B220 antigen is another term for the human protein protein tyrosine phosphatase receptor type C, encoded by the PTPRC gene. The protein is known to function in B cell differentiation and receptor-mediated signaling pathways, among other biological roles. Canonically, it has an amino acid length of 1306 residues and a mass of 147.5 kilodaltons. Its subcellular localization is in the cell membrane and it is expressed in many tissues, such as the appendix and bone marrow. The B220 protein is a member of the Protein-tyrosine phosphatase protein family. Other alias names for B220 include CD45.