CXCR2 and neoplasm: Positive chemokine–chemokine receptor signaling benefits T-cell trafficking into tumors, including that of the signaling pairs CXCL9,10,11/CXCR3, CXCL16/CXCR6, CCL2/CCR2, CCL3, 4, 5/CCR5, CCL21/CCR7 and CCL27/CCR10.305 CAR T cells have been engineered to coexpress CCR2,306 CXCR1 or CXCR2,307,308 and CCR4309 to enhance the ability of T cells to kill tumor cells.