This approach has been successful in the case of Alzheimer’s disease (AD), where tau proteins, total (τT) and phosphorylated (τP), as well as amyloid-β peptides (Aβ) expressing the pathological features of the disease, have been recognized as biomarkers with high diagnostic accuracy and are now included in research diagnostic criteria for AD [10,11,12,13,14,15]. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.