ZW10 interactor isoform b, also known as ZWINT, is clearly involved in kinetochore function. Localized to the cytoplasm during interphase and to kinetochores from late prophase to anaphase, ZWINT interacts with ZW10 (Zeste White 10) and functions to regulate the association between ZW10 and kinetochores. Defects in the gene encoding ZWINT are associated with the pathogenesis of Roberts’s syndrome, an autosomal recessive disorder characterized by growth retardation due to premature chromosome separation. Recombinant human ZWINT protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.