Osteogenic Growth Peptide (OGP) regulates proliferation, differentiation, and matrix mineralization in osteoblast lineage cells. The active portion of OGP, the OGP(10-14) region, is cleaved from the peptide and binds to the OGP receptor which activates the MAP kinase, the Src, and the RhoA pathways. Osteogenic Growth Peptide (OGP) is a native molecule with a primary structure identical to the C-terminus of histone H4, whose sequence contains a highly conserved 14-amino acid motif (NH 2 -ALKRQGRTLYGFGG-OH). This peptide is isolated from blood during osteogenic remodeling of post-ablation of marrow regeneration. The osteogenic growth peptide (OGP) and its C-terminal pentapeptide OGP(10-14) have been shown to stimulate the proliferation, differentiation, alkaline phosphatase activity and matrix mineralization of osteoblastic lineage cells.