CD4 and neoplasm: In in silico and preclinical studies, we have demonstrated that mutated H3K27M peptides are presented on human MHC class I and II within tumor tissues to stimulate proinflammatory mutation-specific CD8+ cytotoxic and CD4+ T helper responses, which are detectable in the peripheral blood of patients spontaneously, and that an H3K27M-specific peptide vaccine is effective against H3K27M-mutant tumors in the above-mentioned MHC-humanized preclinical model [57].