CD8A and cancer: Tumour mutational burden regulates the expression of tumour neoantigens that determine immunogenicity, as somatic mutations generate neoantigen peptides that are expressed via MHC-1 on the cancer cell surface and recognised as foreign by host CD8+ T cells (46); this process does not involve NK cells which, as outlined earlier, identify foreignness via lack of MHC-1 (i.e., ‘missing self’).