Over the last decade, many studies have demonstrated that the unfolded protein response (UPR) markers such as binding immunoglobulin protein (BIP), phosphorylated- (p-) protein kinase double-stranded RNA-dependent (PKR)-like the endoplasmic reticulum (ER) kinase (PERK), p-inositol-requiring enzyme (IRE), and eukaryotic initiation factor 2α (p-eIF2α) were elevated in the most severely affected tissues of AD patients [101–103]. This evidence concerns the gene HSPA5 and Alzheimer disease.