A DNA sequence encoding the human noggin protein sequence (containing the signal peptide sequence, and the mature human noggin sequence) was expressed in modified human 293 cells. Noggin is a secreted glycoprotein predominantly expressed by the dorsal mesoderm during embryogenesis. Noggin has been shown to bind with high affinity to bone morphogenetic protein-4 (BMP-4) and with lower affinity to BMP-2 and BMP-7. Noggin specifically inhibits the action of BMPâ€™s by preventing interaction with their receptors. BMPâ€™s have been shown to promote the differentiation of human embryonic stem cells (hES) into trophoblasts or endoderm cells. This suggests inhibitors of BMP signaling, such as noggin, may be valuable for maintaining hES cells in an undifferentiated state. It has been shown that noggin maintains hES in an undifferentiated state in culture. Additionally, noggin in combination with FGF2 can maintain undifferentiated hES growth for substantial culture periods while retaining hES karyotype and pluripotency. The role of noggin in the maintenance of undifferentiated hES suggests it is potentially a valuable component of animal free hES cultures allowing hES to be applicable for therapeutic applications. Human noggin is a 205 amino acid glycoprotein and is secreted as a covalently linked homodimer of approximately 30 kDa with a similar structure to BMP-7. For additional information on Noggin please refer to Wang G, et al (2005) Biochem Biophys Res Commun. 330(3): 932-942.