CXCL4 is a member of the CXC chemokine family. This chemokine is released from the alpha granules of activated platelets in the form of a homotetramer which has high affinity for heparin and is involved in platelet aggregation. This protein is chemotactic for numerous other cell type and also functions as an inhibitor of hematopoiesis, angiogenesis and T-cell function. Recombinant human CXCL4 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.