Anti-deiodinase, iodothyronine type I antibodies are used in antigen-specific immunodetection in biological samples. The target deiodinase, iodothyronine type I is a known alias name of the protein iodothyronine deiodinase 1, encoded by the DIO1 gene in humans. This 249-amino acid residue protein is known to be important for the deiodination of T4 (3,5,3',5'-tetraiodothyronine) into T3 (3,5,3'-triiodothyronine) and of T3 into T2 (3,3'-diiodothyronine). It is localized to the ER of the cell. Other synonyms for deiodinase, iodothyronine type I include 5DI, THMA2, and TXDI1.