As a result of high plasma levels of PAI-1, fibrinolysis mediated by tissue plasminogen activator (tPA) and urokinase plasminogen-activator (uPA) may be severely reduced [26] and could lead to impaired fibrinolysis, which is frequently seen in COVID-19 patients [27–30] as well as in septic patients [31]. This evidence concerns the gene SERPINE1 and COVID-19.