TLR9 and neoplasm: Indeed, intratumoral administration of the Toll‐like receptor 9 (TLR9) ligand CpG oligonucleotide (CpG) or stimulator of interferon genes (STING) agonist 5,6‐dimethylxanthenone‐4‐acetic acid (DMXAA) can elicit strong antitumor immunity by promoting T cell priming and tumor killing while relieving immune suppression.[18, 19]