Hakaru Hashimoto, in 1912, defined a distinctive hypothyroidism disease in which inflammatory cells infiltrate into thyroid tissue resulting in the production of antibodies against thyroid hormones such as triiodothyronine (T3) and thyroxine (T4) which are synthesized by a pivotal enzyme, namely thyroperoxidase (TPO) [2]. Here, TPO is linked to hypothyroidism.