Anti-MU-1 antibodies are protein reagents that detect specific antigens. The MU-1 antigen is another term for the human protein glutathione S-transferase mu 1, encoded by the GSTM1 gene. The protein is known to function in metabolic processes, among other biological roles. Canonically, it has an amino acid length of 218 residues and a mass of 25.7 kilodaltons. Its subcellular localization is in the cytoplasm and it is notably expressed in the liver. The MU-1 protein is a member of the Mu protein family. Other alias names for MU-1 include GST1, GSTM1-1, and GSTM1a-1a.