Cover photograph (Copyright © 2004, American Society for Microbiology. All Rights Reserved.): Electron micrograph of adenovirus particles with modified minor capsid protein IX. Adenoviruses lacking the pIX gene were propagated on helper cells producing pIX variants with a carboxyl-terminal 30-Å alpha-helical extension with an MYC tag. Surface-accessible MYC epitopes at the tip of the helix were visualized with anti-MYC serum, gold-labeled protein A, and electron microscopy. The nonlabeled virion at the top may result from virus propagation in the untransfected cells in the cultures. (See related article in April 2004: vol. 78, issue 7, p. 3470.).