Anti-Fc receptor like 5 antibodies are used in the immunodetection of the protein encoded by the FCRL5 gene. In humans, the canonical protein has a reported length of 977 amino acid residues and a mass of 106.4 kDa. Its subcellular localization is in the cell membrane. Alternative splicing is reported to yield 5 different isoforms for this protein. It is reported to be expressed in marginal zone B-cells, immunoblasts, tonsillar germinal center centrocytes and in the intraepithelial and interfollicular regions of the tonsil. It is suspected to be involved in B-cell development and differentiation in peripheral lymphoid organs and may be useful markers of B-cell stages. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include fc receptor homolog 5, fcR-like protein 5, immune receptor translocation-associated protein 2, immunoglobulin superfamily receptor translocation associated 2 (IRTA2), and Fc receptor-like protein 5.