Using the CXCR4 antagonist AMD3100, Chen et al. found that inhibition of the SDF-1α receptor (CXCR4) relieved regional immunosuppression and facilitated treatment with anti-PD-1 antibodies in a model of HCC resistant to sorafenib (Chen et al., 2015). The gene discussed is PDCD1; the disease is hepatocellular carcinoma.