Livin isoform beta is a member of the family of inhibitor of apoptosis proteins (IAP) and contains a single copy of a baculovirus IAP repeat (BIR) as well as a RING zinc finger (RZF) domain. Livin isoform beta has direct interaction with several caspases including caspase-3, -7, and –9. This protein inhibits the activation of caspase-9 induced by Apaf-1, cytochrome c, and dATP. Recombinant human Livin beta protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.