Annexin 5 is a member of the annexin family of calcium-dependent phospholipid binding proteins. Annexin 5 is a phospholipase A2 and protein kinase C inhibitory protein with calcium channel activity and a potential role in cellular signal transduction, inflammation, growth and differentiation. In vitro studies have shown that Annexin 5 is a cellular protein which plays a role in the inhibition of blood coagulation by competing for phosphatidylserine binding sites with prothrombin (1). Through affinity assays Annexin 5 has been localized on cells that expressed phosphatidylserine on the cell surface, a feature found in apoptosis as well as other forms of cell death (2). Annexin 5 Protein is ideal for investigators involved in Signaling Proteins, Cellular Proteins, Apoptosis/Autophagy, Cancer, and Neurobiology research.