CD4 and glioma: Soluble factors secreted by glioma cells attract a range of immune cells in tumor microenvironment (TME) including CD4+ and CD8+ T lymphocytes, T regulatory lymphocytes (Tregs), Glioma Associated Microglia/Macrophages (GAMs), Dendritic Cells (DCs), Myeloid-Derived Suppressor Cells (MDSCs) and Natural Killer cells (NKs) that modulate and participate in GB proliferation, invasion and resistance to treatment.