In individuals with a genetic predisposition to Alzheimer’s disease, the immune cells of the brain—the “microglia”—start exerting a protective effect up to two decades before the first symptoms appear. A team from Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) and Ludwig-Maximilians-Universität (LMU) München draws this conclusion based on a study of more than 200 volunteers, which they report in the journal The Lancet Neurology. In light of their study data, the scientists consider modulating the activity of microglia to be a promising therapeutic approach. To this end, they aim to develop drugs that target a cellular receptor called TREM2.