CXCR4 and hepatocellular carcinoma: Currently, sorafenib is a multitargeted tyrosine kinase inhibitor approved as a systemic anti-angiogenic agent for advanced HCC, but its clinical application is limited due to moderate therapeutic efficacy and high incidence of acquired resistance resulted from elevated levels of the CXCL12/CXCR4 signaling induced by prolonged sorafenib treatment (Zheng et al., 2019).