In AD, two types of neuropathological changes can be distinguished, namely positive lesions, appearing due to an accumulation of neurofibrillary tangles (NFTs) formed by hyperphosphorylated tau protein, amyloid β (Aβ) plaques, dystrophic neurites, neuropil threads, and negative lesions, which occur due to brain tissue atrophy, i.e., neural, neuropil, and synaptic loss. This evidence concerns the gene MAPT and Alzheimer disease.