ACKR3 and glioblastoma: Recent studies have shown that chemokine receptors CXCR2, CXCR4, CXCR6, CXCR7, CCR5, CX3CR1 as well as the chemokines CXCL2, IL-8, CCL2 and CX3CL1 are highly expressed in GBM [49,50,51,52,53,54,55,56,57,58,59,60].