While few protein markers of AD (biomarkers of amyloid-beta (Aβ) deposition and of tau-protein-related hyperphosphorylation) are recognized and used in both basic and clinical research in neurodegenerative diseases [50], research needs new biomarkers to better understand the onset and progression of the disease, as well as the complex cascade of biochemical mechanisms that are triggered depending on the stage and the interactions between different pathological processes. The gene discussed is MAPT; the disease is Alzheimer disease.