Anti-FcRH4 antibodies enable researchers to detect and measure the FcRH4 antigen in biological samples. This target is a reported synonym of the FCRL4 gene, which encodes Fc receptor like 4. This protein is known to function in adaptive immune responses and receptor-mediated signaling pathways, among other biological roles. The human version of FcRH4 has a canonical amino acid length of 515 residues and a protein mass of 57.2 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the cell membrane of cells and notably expressed in the tonsil, lymph node, and appendix.