 Activation of cells leads to de-methylation, which exposes CpG regions of host DNA, allowing an inflammatory response to be activated through TLR9.Although it is possible that TLR9 also recognizes unmethylated DNA, TLR9 undoubtedly has a role in phagocytosis-induced autoimmunity.Inflammatory responses mediated by TLR9 pathways can be activated by unmethylated CpG sequences that exist within human mitochondrial DNA.