Adding to this cholinergic hypothesis of AD at a biological level, we and other groups have found that the early growth response-1 (EGR1), a zinc finger transcription factor, plays a significant role in regulating cholinergic functions, such as upregulating gene expression of acetylcholinesterase (AChE) (Hu et al., 2019) and of choline acetyltransferase (Quirin-Stricker et al., 1997). Here, EGR1 is linked to Alzheimer disease.