ANXA5, also known as annexin V, is a member of the annexin family of calcium-dependent phospholipid binding proteins which are involved in membrane-related activity along exocytotic and endocytotic pathways. ANXA5 is a phospholipase A2 and protein kinase C inhibitory protein with calcium channel properties. It functions in signal transduction, inflammation, cell growth and differentiation. ANXA5 is an anticoagulant protein that acts as an indirect inhibitor of the thromboplastin-specific complex, which is involved in the blood coagulation cascade. There are at least ten different annexins in the mammalian species. Annexins do not contain signal peptides, yet some annexins (A1, A2 and A5) appear to be secreted in a physiologically regulated fashion.The binding of labeled ANXA5 to phosphatidylserine is commonly used as a marker of apoptosis.