PECAM1 and endothelial dysfunction: Studies have shown that endothelial dysfunction is associated with EC activation, as indicated by the expression of cell surface markers, including vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and platelet endothelial cell adhesion molecule (PECAM-1; CD31), secretion of angiopoietin-2 (Ang-2) and von Willebrand factor (vWF) [13,14,17].