SERPINE1 and COVID-19: In addition, several published articles have indicated elevated levels of another quantitative marker of plasminogen, that is, the complex of plasminogen: α2-antiplasmin, as well as pro-fibrinolytic components (e.g. plasminogen activators: t-PA and u-PA) and antifibrinolytic components (e.g. plasminogen activator inhibitor (PAI)-1, α2-PI, and TAFI, see the abbreviations) in patients with COVID-19 (40, 41, 65, 103–105).