Anti-FCA/MR antibodies are used in antigen-specific immunodetection in biological samples. The target FCA/MR is a known alias name of the protein Fc alpha and mu receptor, encoded by the FCAMR gene in humans. This 532-amino acid residue protein is known to function as a receptor for the Fc fragment of IgA and IgM. It is localized to the cell membrane of the cell and features N-glycosylated post-translational modifications. In terms of tissue expression, it is noted to be expressed by mesangial cells.