MPO and Venous thrombosis: Several recent studies have also shown a contribution to the formation of Neutrophil Extracellular Traps (NET) in venous thrombosis, and MPO is suspected that MPO is a component of NET.26 After inflammation due to vascular endothelial damage, endothelial cells secrete massive amounts of Von Willebrand Factor (VWF) and P-selectin.