TLR9 and neoplasm: To the extent they are understood, the DNA sensing mechanisms in the target cells comprise two primary adaptor pathways, i.e. toll-like receptor (TLR9) and the stimulator of interferon genes (STING) pathways.[14] Cytoplasmic TLR9 recognizes endogenous ligands, such as danger-associated molecular patterns (DAMPs) like unmethylated DNA sequences [7, 8, 15] The total amount of unmethylated DNA increases in parallel with global DNA hypomethylation in tumor tissue compared to the normal tissue [16].