PDGFA associated protein 1, also known as PDAP1, enhances PDGFA-stimulated cell growth in fibroblasts, but inhibits the mitogenic effect of PDGFB. And its expression is induced by TNF-alpha, and cells overexpressing PDAP1 show significantly less apoptosis on exposure to TNF-alpha. Recombinant human PDAP1 protein, fused to His-tag at C-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.