FST and COVID-19: Circulating levels of markers of endothelial injury (e.g., von Willebrand factor (vWF), soluble thrombomodulin, angiopoietin 2, and follistatin) were higher in hospitalized patients with COVID-19 than in healthy controls, and elevated thrombomodulin, angiopoietin 2, and follistatin levels were correlated with higher mortality rates in patients admitted to the intensive care unit (ICU) [50,51].