SERPINA1 and alpha 1-antitrypsin deficiency: These laboratory investigations are supported by epidemiologic and clinical evidence—either in groups known to be AAT-deficient or in non-select groups—that absolute or relative AAT deficiency increases the risk of COVID-19 infection, more severe disease, and/or greater mortality [73,74,75,76,77,78,79,80,81,82,83,84,85,86].