After surgery and iodine-131 nail clearing/ablation, all of the following conditions must be met simultaneously to determine thyroid cancer cure: 1. no clinical manifestations of tumor (symptoms and signs); 2. no imaging manifestations of tumor (including neck ultrasound and nuclear scan); 3. exclusion of autoantibodies (TGAB) interference, no measurement of serum thyroglobulin in the TSH suppressed state (i.e. TG< 0.1ng/mL), and in the TSH-stimulated state (withdrawal of thyroxine or injection of rh-TSH) TG<1ng/mL.