CXCR4 and neoplasm: In SL4 and CT26 colorectal cancer, tumor-infiltrated Ly6Clo monocytes induced by anti-VEGF therapy can also recruit CXCR2-expressing neutrophils to the tumor site via the CXCL5-CXCR2 and CXCL12-CXCR4 axes (7, 8).