Bone is a dynamic tissue, being continuously remodeled by the coordinated actions of osteoclasts and osteoblast lineage. Osteoblasts, the bone-forming cells, are derived originally from pluripotent mesenchymal stem cells. They synthesize and secrete organic extracellular matrix, osteoid, which is composed primarily of type I collagen. Osteoid is calcified by osteoblasts and during this process the cells become encased in lacunae within the calcified material and become osteocytes. Osteoblasts express protease-activated receptor-1 and vescular endothelial cell growth factor. Studies show that Leukemia inhibitory factor can bind to the osteoblast cell surface and induce bone formation both in vitro and in vivo. The balance between osteoblast recruitment, proliferation, differentiation and apoptosis in sutures between cranial bones is essential for calvarial bone formation.HO-f from AcceGen Biotech Research Laboratories are isolated from human femur. HO-f are cryopreserved at primary cultures and delivered frozen. Each vial contains >5 x 10^5 cells in 1 ml volume. HO-f are characterized by the cytochemically detection of AP and mineral deposition. HO-f are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HO-f are guaranteed for 15 population doublings at the conditions provided by AcceGen Biotech Research Laboratories.