In addition, preparation for RAI therapy requires discontinuation of thyroid hormone or recombinant TSH and a low iodine diet, which reduces quality of life, and the risk of complications associated with repeated iodine-131 treatments with high iodine uptake, such as xerostomia, recurrent sialoadenitis and pulmonary fibrosis, also need to be taken into account (33, 34). The gene discussed is TG; the disease is xerostomia.