Unmethylated CpG deoxynucleotides (CpG ODN) [39,40,41], an agonist of TLR9 that recognize DNA with unmetylated CpG of bacterial and viruses, and polyincosinic-polycytidylic acid (Poly I:C) [42,43], an agonist of TLR3 that recognize the double-stranded RNA of viruses, have been used as an adjuvant to enhance the activation of T cells against cancer cells. This evidence concerns the gene TLR9 and cancer.