Tau protein is identified as a critical component of neurofibrillary tangles, highlighting its role in Alzheimer’s pathology. Researchers identify tau protein as a critical component of neurofibrillary tangles, another hallmark of Alzheimer’s disease. Tau normally helps stabilize the structure of neurons, but in Alzheimer’s, it becomes hyperphosphorylated, leading to the formation of tangles damaging neurons. This discovery highlights the dual-pathology nature of Alzheimer’s—both plaques and tangles are implicated in neuronal death and cognitive decline.