About the Cover: Mitosis is the process by which cells replicate their DNA and divide. Drugs that block mitosis are used to treat various infections and diseases including cancer. Rundle et al. (p 443) use a chemical genetics screen to identify new inhibitors of mitosis and characterize the actions of one of these drugs, ent-15-oxokaurenoic acid (EKA). Unlike other mitosis-arresting drugs, EKA does not inhibit the polymerization of the tubulin. Rather, EKA interferes with the localization of a motor protein, CENP-E to the kinetochore and causes mitotic arrest by inhibiting RanBP2 function. Original fluorescence images of cellular DNA and the mitotic spindle provided by the Roberge laboratory. Cover designed by Theresa M. Dubé.