VAP-1 is a type II cell adhesion membrane?protein belonging to the copper/topaquinone oxidase family. Functionally, VAP-1 is a nonclassical inflammation-inducible endothelial molecule involved in leukocyte-subtype-specific rolling under physiological shear. Molecularly, VAP-1 belongs to a special class of cell surface amino oxidases. The enzymatic reaction itself and the biologically active end products can potentially regulate the adhesive status of the vessel wall. Thus, VAP-1 is an ectoenzyme that has inter-related adhesive and enzymatic functions in regulating physiological trafficking and inflammation. Inhibition of VAP-1 can protect against inflammation related damage to certain injured tissues. This protein is primarily expressed on the high endothelial venules of peripheral lymph nodes and on hepatic endothelia. Additionally, VAP-1 can function as a significant prognostic marker for certain cancers and cardiovascular diseases.