MAPT and Alzheimer disease: Progression of neuropathological changes in the brain of patients with AD might be classified as follows: (i) First stage or AD type 1 positive lesion (due to accumulation), resulting from the accumulation of insoluble protein plaques formed by Aβ/tau in brain tissues that can initiate several biochemistry reactions; and (ii) Second stage or AD type 2 negative lesions (due to losses) with decreased neuron numbers, synapses and cerebral mass loss [7].