APOE and Alzheimer disease: It is hypothesized that AD pathophysiology could be triggered by simultaneous hypocholinergic tone and Aβ accumulation in which Aβ and apolipoprotein E epsilon 4 (ApoE4) could interact with alpha7 nicotinic receptors leading repression of glycogen synthase 3β and downstream effects towards tau protein hyperphosphorylation [26].