Interesting. I think TLR-9 stands for toll-like receptor 9. And these toll proteins were originally studied in fruit fly dorsal ventral patterning and also play

Interesting. I think TLR-9 stands for toll-like receptor 9. And these toll proteins were originally studied in fruit fly dorsal ventral patterning and also play a role in the innate immune system which we share with insects. If this study is right (who knows if it will end up being reproducible), then this would be a great example of how evolution recycles existing proteins to "invent" new stuff. Toll proteins were probably originally involved in body pattern formation, were recycled into a role in innate immunity, and finally in mammals may also play a role in triggering an immune response based DNA damage repair event that plays a role in memory formation.