Autoantibodies for thyroid glands, such as TPO-Ab and Tg-Ab, would be excellent biomarkers for autoimmune thyroiditis, and euthyroid patients with TPO-Ab and/or Tg-Ab should be carefully followed up with regularly repeated thyroid function because of the risks for evolving hypothyroidism (77, 79). This evidence concerns the gene TPO and autoimmune thyroid disease.