To clarify the potential impact of Tg measurement on structural recurrence in TgAb-positive patients with papillary thyroid carcinoma (PTC), we compared the Tg values of our Tg-LC-MS/MS with a commercially available electrochemiluminescence immunoassay for Tg (Tg-ECLIA). The gene discussed is TG; the disease is thyroid gland papillary carcinoma.