The aetiology of AD has not been exactly explained, but several factors are characteristic of the development of disease: the deposition of amyloid β (Aβ) plagues, hyperphosphorylation of microtubule associated protein tau (MAPT), oxidative stress, inflammation process, dyshomeostasis of biometals and a reduction in the level of acetylcholine (ACh) caused by damage to the cholinergic system.2–7. The gene discussed is MAPT; the disease is Alzheimer disease.