TPO and thyrotoxicosis: He was diagnosed with thyrotoxicosis due to GD based on wFT4 of 5.6 ng/dL and TSH of <0.01 mIU/mL and positive TBII at 34% (≤16) and TSIG at 130% (≤125); anti-TPO Ab and anti-TG Ab were positive at 107 IU/mL (<35) and 90 IU/mL (<20), respectively.