Methods for obtaining osteoprogenitors, osteoblasts or osteoblast phenotype cells, as well as cell populations including such cells, from human bone marrow stem cells in vitro or ex vivo are disclosed. Bone marrow stem cells are contacted with human serum or plasma and a growth factor or a biologically active variant or derivative thereof. In addition, osteoprogenitor, osteoblast or osteoblast phenotype cell types and cell populations are provided. The cell populations may include additional cell types, such as endothelial cells or progenitors. The osteoprogenitors, osteoblasts or osteoblast phenotype cells may be used in therapy, particularly bone therapy.
