CHRNA4 and Alzheimer disease: The two main nAChR subtypes found in the brain are α7 and α4β2 (Champtiaux and Changeux, 2002; Dineley et al., 2015) and both of them are related to AD pathogenesis (Wevers et al., 1999; Guan et al., 2000; Gotti et al., 2006; Posadas et al., 2013).