Cover photograph (Copyright © 2001, American Society for Microbiology. All rights reserved.): Glial fibrillary acidic protein (GFAP)-positive astrocytes in the brain of a patient suffering from human immunodeficiency virus type 1 (HIV-1) encephalitis. Reactive astrogliosis, recruitment, and proliferation of astrocytes, a hallmark of HIV-1 encephalitis, are observed in areas of inflammation. Immunohistochemical staining for GFAP is shown. Section is counterstained with Mayer's hematoxylin. Original magnification, ×200. (See related article on page 6572.)