Endotoxemia-induced endothelial fibrosis is characterized by a massive change in the endothelial gene-expression profile, which downregulates endothelial markers, including vascular endothelial cadherin (VE-cadherin) and platelet endothelial cell adhesion molecule 1 (PECAM-1). Here, PECAM1 is linked to serum lipopolysaccharide activity.