Description_x000D_ General description_x000D_ Secreted phosphoprotein 1 (SPP1) or osteopontin is a secreted cytokine. This phosphorylated acidic glycoprotein is expressed in various cells and tissues. It is synthesized by osteoblasts. The gene encoding SPP1 is localized on human chromosome 4q22.1._x000D_ Application_x000D_ Anti-Osteopontin antibody produced in rabbit has been used for ELISA._x000D_ Biochem/physiol Actions_x000D_ A secreted, highly acidic, calcium binding, phosphorylated glycoprotein that is chemotactic for macrophages, smooth muscle cells, endothelial cells, and glial cells. In activated macrophages, OPN inhibits nitric oxide production and cytotoxicity. Human, mouse, rat, pig, and bovine OPN share 40% amino acid sequence identity. Secreted phosphoprotein 1 (SPP1) or osteopontin modulates inflammatory responses and glucose metabolism. It is a chemotactic factor and has a role in immune cell recruitment. The protein is also associated with cell growth, migration and differentiation. SPP1 attaches osteoclasts to the bone matrix. It is also involved in atherosclerotic process and bone mineralization. It is a marker of many cancers._x000D_ Physical form_x000D_ Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 2.5 mg bovine serum albumin._x000D_ Analysis Note_x000D_ The biological activity is measured by its ability to mediate 293 cell adhesion.