CpG ODNs trigger an innateimmune response via Toll-like receptor 9 (TLR9), since they sharesequence analogous to bacterial DNA, thus activating the same immunostimulatorypathway. Hence, CpG molecules stimulateB cells and plasmacytoid dendritic cells (pDCs) and activate bothinnate and adaptive immune responses, making them promising for thetreatment of infectious diseases, cancers, and allergies. However, like other nucleic acids, CpG ODNsare rapidly degraded by DNases. Here, TLR9 is linked to infectious disease.