HSPA5 and Alzheimer disease: Given that the increase in GRP78 results in the activation of PERK/eIF2α in the AD brain during ERS and that it induces the UPR (Chang et al., 2002; O’connor et al., 2008; Ohno, 2014), we further explored the molecular mechanism by which ECH ameliorates ERS using Western blot to evaluate the phosphorylation of PERK and eIF2α in 2 × Tg-AD mice.