Functional adhesion molecule A is found in endothelial and epithelial tight junctions and is involved in the inflammatory enlistment of mononuclear cells containing LFA-1. JAM-A is linked to atherogenesis, platelet activation, transmigration of leukocytes and angiogenesis. JAM-A is also found to be important in the development of many different organ systems, and is mostly expressed in the epithelial parts and the embryonic vasculature. JAM-A is indicated to play a role in epithelial permeability, inflammation and proliferation in the intestine, aiding in homeostasis.