CTLA4 and hepatocellular carcinoma: The latest data suggest that inhibiting the interaction between CXCR4 expressing T cells and CXCL12 secreting cells in the microenvironment may modulate anti-CTLA-4 or anti-PD-1 immunotherapy in pancreatic cancer and HCC (Feig et al., 2013; Chen et al., 2015).