Anti-FCRIII antibodies are protein reagents that detect specific antigens. The FCRIII antigen is another term for the human protein Fc gamma receptor IIIa, encoded by the FCGR3A gene. The protein is a known receptor for the invariable Fc fragment of immunoglobulin gamma (IgG). Canonically, it has an amino acid length of 254 residues and a mass of 29.1 kilodaltons. Its subcellular localization is in the cell membrane and is secreted. It is reported to be expressed in natural killer cells.