BNSP, Bone sialoprotein 1, BSP I, BSPI, Early T lymphocyte activation 1, ETA 1, ETA1, MGC110940, Nephropontin, OPN, osteopontin/immunoglobulin alpha 1 heavy chain constant region fusion protein, OSTP_HUMAN, OSTP_MOUSE, secreted phosphoprotein 1 (osteopontin, bone sialoprotein I, early T-lymphocyte activation 1), Secreted phosphoprotein 1, SPP 1, SPP-1, SPP1, SPP1/CALPHA1 fusion, Urinary stone protein, Uropontin
Osteopontin is the principal phosphorylated glycoprotein of bone and is expressed in a limited number of other tissues including dentine. Osteopontin is produced by osteoblasts under stimulation by calcitriol and binds tightly to hydroxyapatite. It is also involved in the anchoring of osteoclasts to the mineral of bone matrix via the vitronectin receptor, which has specificity for osteopontin. Osteopontin is overexpressed in a variety of cancers, including lung, breast, colorectal, stomach, ovarian, melanoma and mesothelioma.
