High titers of anti-thyroid peroxidase (anti-TPO) or anti-thyroglobulin (anti-Tg)antibodies in serum confirm the diagnosis; Serum titers of thyroid stimulatinghormone (TSH) and free T4 (FT4) hormone measurements and imaging studies, such asthe ultrasound (US), are used to diagnose Hashimoto's thyroiditis. This evidence concerns the gene TPO and Hashimoto thyroiditis.