Thyroid peroxidase (TPO) is an enzyme crucial for the synthesis of thyroid hormones. It is located on the thyroid gland's follicular cells and plays a vital role in the iodination of tyrosine residues in thyroglobulin, a precursor for thyroid hormones. TPO catalyzes the oxidation of iodide ions to iodine, which then iodinates the tyrosine residues, leading to the production of thyroid hormones such as thyroxine (T4) and triiodothyronine (T3).
