ACHE and Alzheimer disease: Since AD has multifactorial and complex pathophysiology, a pair of hypotheses have been so far proposed, known as the ”amyloid hypothesis” and “cholinergic hypothesis.” Based on the cholinergic hypothesis approach, the most prescribed drug class against the disease is AChE inhibitors, as an apparent deficit in acetylcholine (ACh) is shown to occur in the brains of AD patients.