PECAM1 and chronic obstructive pulmonary disease: For the final transendothelial migration, the interaction between two platelet/endothelial cell adhesion molecules (PECAM)-1, expressed at the endothelial cell boundary and on neutrophils, is essential for the ultimate transendothelial migration.83,84 Selectin L, E and P have been found in COPD.85 PSGL-1 levels were higher in all stable COPD patients than those in in healthy controls.86 Increased E-selectin and serum ICAM-1 have also been reported in COPD patients.87,88 During migration, the neutrophils release substantial amounts of proteinases and ROS.