IL6 and thyroid gland disorder: Moreover, the patients with thyrotoxicosis (TSH < 0.34 mIU/l) had significantly higher levels of the mean serum IL-6 than those without thyrotoxicosis (P < 0.05) (most of them > 10 pg/ml with the reference range < 6.4 pg/ml), suggesting inflammation due to COVID-19 infection, as indexed by elevated IL-6, was a driving force for the thyroiditis.