The “cholinergic hypothesis” of AD (Bartus et al., 1982) gained momentum with the finding that acetylcholinesterase inhibitors (AChEIs) have significant symptomatic effects in AD patients (Summers et al., 1986) This led to the development of a larger family of acetylcholinesterase inhibitors (AChEIs) (Hampel et al., 2018) (Figure 2E–G), which remains one of the few classes of FDA approved drugs for the treatment of AD (Johannsen, 2006; Mangialasche et al., 2010; Hampel et al., 2018). Here, ACHE is linked to Alzheimer disease.