CXCR4 and neoplasm: Moreover, significant reduction in tumor size and complete remission have been observed with CCR2b-GD2-CAR T cells and CXCR4-EGFRvIII-CAR NK cells infused in mice bearing CCL2 producing GD2 neuroblastoma or CXCL12 secreting EGFRvIII glioblastoma cells, respectively (168, 169).