Cover photograph (Copyright © 2004, American Society for Microbiology. All Rights Reserved.): HeLa cells stained for tubulin (yellow) and DNA (blue). A normal mitotic HeLa cell (upper left) and a series of cells undergoing aberrant mitoses when depleted of the spindle protein HEI-C are shown. (See related article in May 2004, vol. 24: issue 9, 3957.)