TPO and hyperthyroidism: His thyroid function tests (Table 2) revealed hyperthyroidism with a fT3 6.27 pmol/L (3.8-6.0 pmol/L), fT4 18.19 pmol/L (7.86-14.41 pmol/L), TSH 0.08 μIU/mL (0.34-5.6 μIU/mL), thyroglobulin 140.6 ng/mL (1.15-50 ngmL), anti-TPO antibody 94 IU/mL (0-9 IU/mL), anti-thyroglobulin antibody <0.9 IU/mL (0-4 IU/mL), and anti-TSH receptor antibody 5 IU/L (<1 IU/L).