During the radioactive iodine treatment of the patients, while routine blood tests (serum thyroid stimulating hormone, thyroglobulin and anti-thyroglobulin antibody) were performed before hospitalization, approximately 2 mL of blood was taken into Paxgene tubes, which will provide RNA stabilization, in the same session, and these blood were stored at -80 °C until all patients were completed. Blood was collected from a similar number of healthy volunteers in the same way as in the patient group and stored.