APP and Alzheimer disease: The behavior and clinical development of AD seems to be associated with the senile plates formed by the ß-amyloid protein derived from the cleavage of amyloid precursor peptide (APP) [79–81], a process that occurs as a function of gene mutation [82] and, nowadays, Positron Emission Tomography has the ability to indicate the presence of ß-amyloid in the brain [83], as well as Magnetic Resonance Imaging [84]; however, this protein also exists in brains of normal aging people.