CXCR4 and hepatocellular carcinoma: EpCAM is not only a tumour biomarker of HCC 30, 31 but also an important molecule for promoting metastasis of HCC cells 32; K19, MMP2/9 and CXCR4 also played a pivotal role in promoting metastasis of HCC cells 9, 11, 15, 33, 34.