Apolipoprotein E isoforms and regulation of the innate immune response in brain of patients with Alzheimer's disease

► Largest genetic risk for late-onset Alzheimer's disease resides at the APOE gene. ► Innate immune response is consistently observed in AD and a possible contributor. ► apoE isoforms regulate multiple facets of innate immune response in brain. ► apoE isoforms may alter AD through both Aβ-dependent and Aβ-independent mechanisms.