CXCR4 and glioblastoma: Other ongoing immunotherapeutic approaches for glioblastoma clinical trials, antibody-drug conjugates (ADC), MDSC and GAM-targeting therapy, anti-angiogenesis therapy, C-X-C chemokine receptor type 4 (CXCR4 or CD182) inhibitor, oncolytic viral therapy, CAR T cell therapy, immune-stimulators, receptor tyrosine kinase (RTK) inhibitors or in combination are also currently being tested extensively in multiple clinical trials [1, 3, 4].