IGFBP6 contains 1 IGFBP N-terminal domain and 1 thyroglobulin type-1 domain. IGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors. Recombinant human IGFPB6 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.