MAPT and Alzheimer disease: According to the toxic oligomer hypothesis of AD, the cascade of the neurotoxic effects of Aβ and tau includes neuroinflammation, mitochondrial dysfunction, metabolic dysregulation, and protein degradation deficiency, leading to metabolic and oxidative stress, excitotoxicity, defective neurogenesis and neurodevelopment, synaptic damage, axonal transport dysfunction, iron accumulation, and loss of neurons due to apoptosis, necroptosis, necrosis, pyroptosis, ferroptosis, and others [11,159,160,161,162,163] (Figure 3).