APOE and Alzheimer disease: In humans with mild cognitive impairment and AD, the APOE ε4 allele was associated with higher risk of cerebral cortex microbleeds in men than in women, although that was also dependent on other risk factors, such as hypertension, diabetes, and age (Shams et al., 2015; Cacciottolo et al., 2016; Finch and Shams, 2016).