KDR and hepatocellular carcinoma: Because immune checkpoint blockade combined with sorafenib (a pan-VEGFR inhibitor) has led to improved immune cell infiltration and productive anti-tumor immunity in hepatocellular carcinoma (HCC) patients [175], several combination regimens have been approved by the Food and Drug Administration (FDA) for clinical trials, and the concept of combining vascular normalization therapy with immunotherapy is currently in clinical practice [150,176].