Scientists have identified the molecular system that contributes to the harmful inflammatory reaction in the brain during neurodegenerative diseases. An important aspect of chronic neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, Huntington’s or prion disease, is the generation of an innate inflammatory reaction within the brain. Results from the study open new avenues for the regulation of the inflammatory reaction and provide new insights into the understanding of the biology of microglial cells, which play a leading role in the development and maintenance of this reaction.