Our previous findings demonstrated that targeting the VEGF-induced proangiogenic CXCL12/CXCR4 signaling pathway15, 16 with an OV expressing a CXCR4 antagonist fused in-frame with the Fc portion of murine IgG (OV-CXCR4-A) effectively inhibited the recruitment of circulating endothelial progenitor cells (CEPs) into the TME in breast and OC-bearing mice17, 18 along with inhibition of cancer-associated fibroblasts (CAFs)19, myeloid-derived suppressor cells (MDSCs)20, and regulatory T (Treg) cells21. The gene discussed is CXCR4; the disease is cancer.