Finally, SHBG levels have also been associated with thyroid hormone levels.[24] Patients in the ICU often have decreased levels of thyroid hormones, such as tri-iodothyronine and thyroxine, which is known as non-thyroidal illness syndrome and associated with a poor prognosis.[25] This might also explain the lower SHBG levels we found, since low tri-iodothyronine levels have also been described in COVID-19 patients and were associated with severity of the disease.[26,27]. This evidence concerns the gene TG and COVID-19.