In AD brains, compacted Aβ plaques are often associated with activated astrocytes and microglia and a variety of cytokines and other inflammatory proteins secreted by activated astrocytes or microglia, including Clq, C3, C9, C3d, and C4d, which are found in brains from human AD patients and mouse models of AD [48-50]. This evidence concerns the gene C3 and Alzheimer disease.