CXCL8 and glioblastoma: Glioma-derived factors such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)- 1α and 1β, IL-4, IL-6, IL-8, chemokines (e.g., CXCL-12), cyclooxygenase-2 (COX-2), prostaglandin (PG) E2, and platelet-derived growth factor (PDGF) are the crucial inflammatory mediators that trigger the inflammatory cycle in GBM and also promote carcinogenesis via evading growth suppression, inducing angiogenesis and metastasis, resisting apoptosis, and maintaining cancer cells stemness [20,27,28,29].