Anti-FcgammaRI antibodies are protein reagents that detect specific antigens. The FcgammaRI antigen is another term for the human protein Fc gamma receptor Ia, encoded by the FCGR1A gene. The protein is a high affinity receptor for the Fc region of immunoglobulins gamma. Canonically, it has an amino acid length of 374 residues and a mass of 42.6 kilodaltons. Its subcellular localization is in the cell membrane and it is reported to have monocyte/macrophage specific expression. The FcgammaRI protein is a member of the FCGR1 protein family. Other alias names for FcgammaRI include CD64, CD64A, and FCG1.