Thyroid peroxidase, or, TPO, is a human gene. Other names include: TPO; MSA; TDH2A; TPX. The encoded protein is an enzyme with an amino acid length of 933 and a mass of 103.0 kDa. Thyroid peroxidase is a member of the Peroxidase family, XPO subfamily. This gene shares homology with other species, including: Mouse, Arabidopsis, Frog.