CXCR4 and hepatocellular carcinoma: Recently, we have found that alpha fetoprotein (AFP), a specific biomarker of HCC, harbours a function to activate phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (AKT) signal pathway to stimulate expression of metastasis‐related factor, such as CXC motif chemokine receptor 4(CXCR4) 5.