Igfbp6, also known as insulin-like growth factor-binding protein 6, binds insulin-like growth factor 1(IGF-1) and IGF-2 with high affinity and inhibits IGF action in vitro. It is a cysteine-rich protein with conserved cysteine residues, which are clustered in the amino- and carboxy-terminal thirds of the molecule. It plays a key role in the regulation of IGF bioavailability, by modulating its molecular size, capillary membrane permeability, target tissue specificity, cell membrane adherence and IGF affinity. Recombinant mouse Igfbp6, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.