FDCSP is a small secreted protein that is in follicular dendritic cells. This protein specifically binds to activated B cells, and functions as a regulator of antibody responses. It is also thought to contribute to tumor metastases by promoting cancer cell migration and invasion. Recombinant human FDCSP protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.