who demonstrated that TLR9 is absolutely required for all cellular responses to CpG DNA 2. The authors have shown that cells derived from TLR9-deficient mice are unresponsive to CpG stimulation.

This discovery provides insights into the functional differences among three classes of CpG oligodeoxynucleotides ... The intracellular role of ADA2 in TLR9 activation was investigated, as ...