STIP1, also known as stress-induced-phosphoprotein 1 isoform b, belongs to the large group of co-chaperones. The main function of STIP1 is to link Hsp70 and Hsp90 together. STIP1 also modulates the chaperone activities of the linked proteins and possibly interacts with other chaperones and proteins. It forms a complex with HSC70 and HSPCA/HSP-86 and HSPCB/HSP-84, as well as interacting with PACRG. Recombinant human STIP1 was expressed in E.coli and purified by using conventional chromatography techniques