CD4 and glioblastoma: A similar study in GBM tumor tissues revealed that bacterial peptides, derived mainly by the GBM-abundant phyla Firmicutes and Proteobacteria, were presented as complex with HLA-class II antigens expressed on tumor cells, thus stimulating multiple TIL-derived CD4+ T cell clones for secretion of proinflammatory cytokines and chemokines [118].