APP and Hypertension: One might expect that there would be synergism between effects of hypertension and AD on APP processing, since hypertension models suggest that with aging hypertension increases the activity of β-secretase (not mRNA) as well as APP binding proteins (Csiszar et al., 2013; Zhang et al., 2018, 2019) and in AD models, expression of β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) can be upregulated by oxidative damage or inflammation (Zhang et al., 2018).