ATF4 and Alzheimer disease: In the APP23 AD model mice, after long-term feeding with quercetin, a polyhydroxylated flavonoid, the expression of growth arrest and DNA damaged-inducible gene 34 (GADD34) was induced, leading to the down-regulation of phosphorylated-eIF2α and ATF4 (Ohta et al., 2011; Hayakawa et al., 2015).