Of 10 benign nodules with the highest PTN/Tg ratio, 2 occurred in patients with Graves’ disease (2 of 2 subjects with Graves’ disease), 1 in a subject with a follicular adenoma (1 of 4 subjects with follicular adenoma), 1 in a patient with chronic lymphocytic thyroiditis (1 of 3 subjects with chronic lymphocytic thyroiditis), 1 in a benign nodule adjacent to PTC and 5 in benign nodules without other significant histological findings. Here, TG is linked to follicular thyroid adenoma.