AIT, also known as Hashimoto’s thyroiditis (HT) or chronic lymphocytic thyroiditis, is the most common cause of hypothyroidism (28), characterized by thyroid infiltration by inflammatory cells and the presence of antithyroglobulin antibodies (anti-TG Ab) or anti-thyroid peroxidase antibodies (anti-TPO Ab). The gene discussed is TPO; the disease is hypothyroidism.