Figure 1.

Combination therapeutic strategy modulating the immunosuppressive microenvironment for cancer treatment. Increased intratumoral hypoxia after sorafenib treatment–caused by reduced microvascular density (MVD)–increased expression of PD-L1 and SDF-1α, and the recruitment of immunosuppressive bone marrow-derived cells (BMDCs) and regulatory T cells (Tregs) in hepatocellular carcinoma (HCC). These effects were prevented when combining sorafenib with AMD3100, a CXCR4 antagonist, which facilitated immunotherapy with anti-PD-1 antibodies.