We recently reported that six-month-old (hAPP) mice, which contain the Swedish, Iberian, and Arctic mutation (APP NL-G-F) (AppNL-G-F), show impaired cognitive performance that is associated with increased hippocampal DNA methylation of a 1 Kb region overlapping the 3’UTR of the Tomm40 gene and the promoter region of the Apoe gene (Kundu et al., 2021), both genes that modulate AD risk (Roses et al., 2016). Here, APOE is linked to Alzheimer disease.