CD4 and glioblastoma: As it is evidenced that several genes (including TP53, BRCA1 etc.)are regulated by DNA methylation in other cancers [34–37] we also believe altering the DNA methylation in the tumor infiltrating CD4+ T cells, especially the key lineage specific transcription factors and key cytokines is an inherent characteristic of GBM to regulate effector phenotypes in these cells.