In brain sections, monoclonal anti-CR1 Abs 8C9.1 (Fig 3A, 3B and 3D–3F) and J3B11 (Fig 3G–3I) labeled cell bodies and processes of cells with the characteristic morphology of astrocytes in all 9 nondemented cases and 14 AD cases (Table 2). This evidence concerns the gene CR1 and Alzheimer disease.