NREP, as known as neuronal regeneration-related protein, has roles in neural function. It promotes axonal regeneration. It may also have functions in cellular differentiation. This protein induces differentiation of fibroblast into myofibroblast and increases retinoic-acid regulation of lipid-droplet biogenesis. Recombinant human NREP protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.