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 draws this conclusion based on a study of more than 200 volunteers. 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.