ACE2 and COVID-19: ACE-2 expression levels are relatively higher in the thyroid gland and heart, than in the lung.[18] Approximately 15% of adults with COVID-19 infection have abnormal thyroid function, and circulating triiodothyronine levels are associated with adverse COVID-19 outcomes.[19,20] Therefore, physicians should be aware of the possibility of thyroid dysfunction in patients with COVID-19.