APOE and Alzheimer disease: Moreover, immunohistochemical analysis revealed that harboring APOE-ε4 in AD is associated with less microglial coverage of Aβ plaques (that is, decreased proportion of Aβ colocalized with Iba-1+ microglia) in females (females, β = −2.818, P < 0.01; males, β = −0.965, P = 0.327; Extended Data Fig. 7d,e).