{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Thyroglobulin (Tg) is a 660 kDa, dimeric protein produced by and used entirely within the thyroid gland. Tg is used by the thyroid gland to produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The active form of thyroxine, triiodothyronine, is produced both within the thyroid gland and on the periphery by 5’-deiodinase, which has been referred to as Tetraiodothyronine-5-deiodinase."}]},{"type":"paragraph","children":[{"type":"text","value":"This antibody reacts with human thyroglobulin as demonstrated by a single band of immunoblotting in a lysate of human thyroid tissue. The vast majority of follicular carcinomas of the thyroid will give positive immunoreactivity for thyroglobulin, sometimes only focally. Poorly-differentiated Carcinomas of the Thyroid are frequently thyroglobulin negative. Adenocarcinomas of non-thyroid origin do not react with this antibody."}]}]}