GSKIP (GSK3 β interaction protein) is defined as a naturally occurring protein that is homologous with the GSK3beta interaction domain of Axin and is able to negatively regulate GSK3beta of the Wnt signaling pathway. GSKIP may affect GSK3β activity on neurite outgrowth by inhibiting the specific phosphorylation of tau (ser396). Recombinant human GSKIP protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.