NOG, also known as noggin, is a secreted protein involved at multiple stages of vertebrate embryonic development including neural induction and is known to exert its effects by inhibiting the bone morphogenetic protein(BMP)-signaling pathway. It binds several BMPs with very high affinities, with a marked preference for BMP2 and BMP4 over BMP7. It plays a key role in neural induction by inhibiting BMP4, along with other TGF-beta signaling inhibitors such as chordin and follistatin. Recombinant human NOG, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.