The APOE e4 allele has been linked to poorer cognitive performance and greater cognitive decline in older adults (Nilsson et al., 2006; Brewster et al., 2014; Zhen et al., 2017; Todd et al., 2018; Gharbi-Meliani et al., 2021), and APOE e4 may increase vulnerability to cognitive effects of Alzheimer’s disease (AD) pathology (Weigand et al., 2021). The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.