TSHR and hyperthyroidism: The cause of hyperthyroidism in GD is circulating autoantibodies directed against the thyrotropin receptor (TSHR), which mimic the action of TSH and excessively activate thyroid follicular cells and consequently stimulate the secretion of thyroid hormones (triiodothyronine and thyroxine), thereby inducing thyroid growth and its vascularization [3].