The plasma levels of Von Willebrand factor (VWF), angiopoietin-2, Fms-related tyrosine kinase 3 ligand (FLT-3L), and plasminogen activator inhibitor type (PAI)-1 are significantly elevated in patients with COVID-19, further supporting the hypothesis of SARS-CoV-2-induced endothelial dysfunction or damage (30, 31). Here, FLT3LG is linked to COVID-19.