HSPA5 and Alzheimer disease: ER stress marker immunoglobulin-binding protein (BiP)/GRP78 and UPR-transducer proteins, such as phosphorylated pancreatic ER kinase (p-PERK), eukaryotic initiation factor 2 (eIF2α), inositol-requiring enzyme 1 (IRE1), and activating transcription factor-6 (ATF6), were detected in the hippocampal neurons of AD [10, 11].