Cover photograph (Copyright © 2003, American Society for Microbiology. All Rights Reserved.): Internalization of Streptococcus pyogenes (group A Streptococcus [GAS]) to influenza A virus (IAV)-infected alveolar epithelial cells. A mouse was infected intranasally with IAV on day -2 and GAS on day 0, and then lungs were harvested 24 h after the GAS infection. Lung sections were stained with Alexa Fluor 568-conjugated anti-IAV hemagglutinin monoclonal antibody (red) or polyclonal rabbit antibody against GAS and fluorescein isothiocyanate-conjugated anti-rabbit immunoglobulin G (green). Image was visualized under a confocal microscope. The photo shows that the GAS was associated with IAV-infected alveolar epithelial cells (yellow). (See related article on page 4104.)