As suggested by prior literature, APOE-ε4 has a greater impact on AD pathology, particularly amyloid burden (Morris et al., 2010; Resnick et al., 2015; Toledo et al., 2015; Pletnikova et al., 2018; Baek et al., 2020), rather than directly on white matter integrity, although we cannot rule out the possibility that APOE-ε4 affects axonal and synaptic integrity in ways that are not measurable through current DTI technologies (Adalbert et al., 2007). The gene discussed is APOE; the disease is Alzheimer disease.