Thyroid follicular cells have receptors for ACE2 and transmembrane serine protease 2 (TMPRSS2), which facilitate the invasion of SARS-CoV-2, triggering an inflammatory cascade and a hyperreactive immune response, culminating in thyroid dysfunction caused by both autoimmune thyroid disease (AITD) and non-thyroidal illness syndrome (NTIS) [12]. The gene discussed is TMPRSS2; the disease is autoimmune thyroid disease.