EIF2AK3 and Alzheimer disease: Furthermore, chronic expression of Aβ42 activates protein kinase R-like endoplasmic reticulum kinase (PERK) and ATF6 pathways, both major branches of the unfolded protein response, as well as inositol-requiring enzyme 1 α-XBP1 pathway, and Aβ42-induced activation of PERK may have a beneficial effect on AD by Aβ42 clearance [124].