The findings summarized in this review indicate that BACE1-mediated insulin resistance may be one of the key events situated at the intersection between AD and DM, although further investigation is needed to fully understand how this pathogenic mechanism may underlie the complex, bidirectional connections between the CNS and peripheral tissues (Arnold et al., 2018; Rhea et al., 2022). This evidence concerns the gene BACE1 and Alzheimer disease.