TLR9 and cancer: Herein, we developed a cancer immunotherapy based on MNP covalently modified with an antigen peptide (a cysteine-modified class I restricted epitope of ovalbumin, Cys-OVA257-264, COVA) and an oligonucleotide adjuvant (CpG ODN1826, an agonist of murine Toll-like receptor 9, TLR9 [30]) via disulfide bonds (MNP-CpG-COVA).