os·te·o·pon·tin 
(ŏs′tē-ō-pŏntn)
(ŏs′tē-ō-pŏntn)n.
A phosphorylated glycoprotein that is produced by bone, is abundant in bone mineral matrix, and accelerates bone regeneration and remodeling. It is also produced in other tissues and plays a role in the progression of many diseases, including certain cancers.
[OSTEO- + Latin pōns, pont-, bridge; see pent- in the Appendix of Indo-European roots + -IN.]