APOE and Cognitive impairment: These impairments have been observed in patients with mild cognitive impairment (Salek et al., 2011), in the early stages of dementia due to AD (Tippett et al., 2012; de Boer et al., 2014, 2015, 2016), and in individuals at an increased risk for future dementia (due to a dementia family history, or a genetic risk due to being an APOE e4 carrier) who did not yet show any cognitive deficits (Hawkins and Sergio, 2014; Lu et al., 2021).