AD can be classified as organ-specific or systemic, depending on whether the autoimmune response is directed against a particular tissue as has been described in chronic lymphocytic thyroiditis (Hashimoto's thyroiditis) where circulating antibodies against thyroid peroxidase and thyroglobulin can be found [2], or against widespread antigens such as anti-nuclear antibodies in systemic lupus erythematosus (SLE) [3]. The gene discussed is TPO; the disease is Hashimoto thyroiditis.