Interestingly, the APOE4 allele is responsible for an increased inflammatory and neurotoxic response of microglia and astrocytes in the brain of carriers (Arnaud et al., 2022; Serrano-Pozo et al., 2021; Rodriguez et al., 2014), and it was noted that the majority of the other germline AD-risk variants are located within or near genes expressed in microglia McQuade and Blurton-Jones, 2019 and in particular at microglia-specific enhancers (Nott et al., 2019). Here, APOE is linked to Alzheimer disease.