However, the induction of TLRs, especially TLR9, in tumor cells by endogenous ligands not only fails to result in antitumor immunity but rather contributes to tumor progression 18, 23, 24, 27, which may contribute to the failure of TLR9 agonists in systemic antitumor therapy in clinical trials 16, 17. This evidence concerns the gene TLR9 and neoplasm.