BACE1 and Alzheimer disease: Consistent with previous reports (Preece et al., 2003; O’connor et al., 2008; Kim et al., 2018), the results (Figure 4C) showed that there was no significant difference in BACE1 mRNA among the four indicated groups, even though the mRNA level in ECH-treated 2 × Tg-AD mice exhibited an increasing trend compared with vehicle-treated 2 × Tg-AD.