CD4 and neoplasm: In addition, 80–90% of immunogenic neoantigen epitopes screened from three different mouse models of melanoma, colon cancer and breast cancer are recognized by CD4+ T cells rather than CD8+ T cells, suggesting that tumour-specific neoantigens may bind more easily to MHC class II molecules than to MHC class I molecules with more restrictive characteristics [47,48,49].