Cholinesterases, such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), are enzymes responsible for acetylcholine cleavage, and their inhibition, with the consequent enhancement of cholinergic transmission, represents the therapeutic approach most widely exploited for the treatment of Alzheimer’s disease, albeit only palliative. The gene discussed is ACHE; the disease is Alzheimer disease.