Participants received either of two vaccine strategies, each of which included a cocktail of short peptide antigens for CD8+ T cells (12MP): in addition, participants received either a tetanus toxoid peptide that stimulates CD4+ T cell responses (tet)5 or a cocktail of 6 melanoma-specific peptides antigens for CD4+ helper T cells (6MHP)7. This evidence concerns the gene CD4 and tetanus.