APOE and Alzheimer disease: APOE4 is associated with increased AD risk through mechanisms such as enhanced Aβ aggregation, intraneuronal Aβ accumulation, early Aβ seeding, amyloid plaque formation, and CAA pathology (Christensen et al., 2010; Koffie et al., 2012; Kok et al., 2009; Liu et al., 2017; Polvikoski et al., 1995; Rannikmae et al., 2014; Schmechel et al., 1993; Shinohara et al., 2016; Tiraboschi et al., 2004).