PPP1R15A and Alzheimer disease: Quercetin and its metabolites have been reported to act on several signaling pathways, including cAMP-response element binding protein (CREB), c-Jun N-terminal kinases, the mitogen-activated protein, macroautophagy, calcium homeostasis, proteasomal degradation and GADD34-eIF2α-ATF4 pathways that participate in AD pathogenesis [29-32].