Anti-family with sequence similarity 134 member A antibodies are protein reagents that detect specific antigens. The family with sequence similarity 134 member A antigen is another term for the human protein reticulophagy regulator family member 2, encoded by the RETREG2 gene. Canonically, it has an amino acid length of 543 residues and a mass of 57.8 kilodaltons. Its subcellular localization is in the ER and it is expressed in many tissues, such as the cerebral cortex and testis. The family with sequence similarity 134 member A protein is a member of the RETREG protein family.