A 42-year-old man had mild liver dysfunction on presentation with hyperthyroidism due to Graves’ disease (GD): ALT 65 (0–45 IU/L), fT4 41.2 (9–23 pmol/L), fT3 > 30.7 (2.4–6 pmol/L), and TSH < 0.01 (0.3–4.2 mIU/L). The gene discussed is GPT; the disease is Graves disease.