CXCL12 and hepatocellular carcinoma: To further verify whether SDF-1/CXCR4 signaling is the key contributor to EPCs’ homing process in response to the EphA1 level change in HCC cells, we performed an IP assay using the lysates from EPCs after they were co-cultured with IgG-Fc- or ephrinA1-Fc-stimulated HLE cells and the SDF-1 antibody, followed by a WB assay of the immunoprecipitated eluate (IP eluate) for CXCR4.