CXCL12 and glioblastoma: Certainly, for its formation and progression, GBM cells engage different chemokines such as CXCL8, CXCL16, CX3CL, CCL5, CXCL12, and their receptors CXCR1-2, CXCR6, CX3CR1, CCR5, CXCR4-7, respectively, for a chemokine network communication mechanism to maintain and increase the tumor malignancy (Table 1).