Etiologies such as infection or trauma were excluded, along with thyroid auto-immune conditions, by measuring anti-TSH receptor antibody (TRAb), thyroid-stimulating immunoglobulin antibody (TSI), thyroid peroxidase (TPOAb), and anti-thyroglobulin (TgAb) antibodies, the results of which were all negative. Here, TG is linked to thyroiditis.