Most information about the cause of Alzheimer's is based on studies from animal models. Now, a study examines the brain tissue of deceased human patients and sheds light on dysfunctions in molecular networks in the brain that are at the root of Alzheimer's. By showing that the TYROBP gene plays a key role in disrupting immune system pathways in the brains of Alzheimer's patients, the study reveals a potential therapeutic target for preventing brain damage.