In the more common form of the disease, late onset AD (LOAD), APOE has been established unequivocally as a susceptibility gene (Saunders et al., 1993) with several dozen other genetic loci receiving genetic support (Carmona et al., 2018; Jansen et al., 2019; Kunkle et al., 2019). Here, APOE is linked to Alzheimer disease.