CXCR4 and neoplasm: A phase 2 clinical trial using CXCR4 antagonist BL-8040 and pembrolizumab in metastatic pancreatic patients (NCT02907099) showed that the application of BL-8040 and pembrolizumab could increase the quantity of T cell infiltration in tumor tissues, but was accompanied by 26.67% severe adverse events and 33.33% non-severe adverse events.