Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Ebola virus matrix protein VP40 colocalizes with microtubules inside cells and with vacuolar protein-sorting protein TSG101 on the cell surface. Clockwise from bottom left, this composite shows tubulin (blue), VP40 (green), TSG101 (red), and a merged image indicating overlap of VP40 and tubulin as cyan and overlap of VP40 and TSG101 as yellow. (See related article on page 4709.)