SELL and COVID-19: Analysis of several biomarkers of endothelial function revealed increased blood levels of soluble VCAM-1 (sVCAM-1) and vascular endothelial growth factor (VEGF) and decreased levels of soluble L selectin shed from activated neutrophils (sL selectin; also known as sCD62L) and soluble CD31 (sCD31; also known as sPECAM-1) in patients with COVID-19 compared with HVs (Figure 4, Supplemental Figure 12, and Supplemental Table 3).