Increased nasopharyngeal ACE2 levels are protective and the TMPRSS2/ACE2 ratio is associated with risk of COVID-19 with prevalent symptomatology (cough, 70.42%; fever, 63.85%; headache, 61.50%; anosmia, 57.28%; myalgia, 55.87%) [212]. Here, ACE2 is linked to COVID-19.