Another characteristic feature of AD is the abnormal accumulation of tau protein in the form of neurofibrillary tangles within neurons. Tau protein plays a crucial role in stabilizing microtubules, which are essential for maintaining the structure and function of neurons. In AD, tau protein becomes hyperphosphorylated, leading to its misfolding and aggregation into neurofibrillary tangles (Figure ). These tangles interfere with intracellular transport and contribute to neuronal dysfunction and cell death.