In summary, the most significant and novel finding of this study is that the activation of the ephrinA1/EphA1 pathway in HCC cells can significantly increase the expression and secretion of SDF-1 in the tumor microenvironment, thus promoting tumor angiogenesis by enhancing the homing and tube formation abilities of EPCs in a paracrine fashion. The gene discussed is CXCL12; the disease is neoplasm.