Platelet endothelial cell adhesion molecule 1 (PECAM-1; CD31) and intercellular adhesion molecule 1 (ICAM-1; CD54) are adhesion molecules found on the surface of activated endothelium as well as on some immune cells including monocytes and their expression is upregulated in experimental AP (141). Here, PECAM1 is linked to alkaline phosphatase measurement.