Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Biarsenical two-color labeling of a HeLa cell expressing tetracysteine-tagged human immunodeficiency virus type 1 Gag reveals the location of steady-state Gag in red (ReAsH labeled) and newly synthesized Gag (i.e., Gag produced after 2.5 h) in green (FlAsH labeled) by deconvolution fluorescence microscopy analysis. Total Gag is labeled by p6^Gag antiserum (blue). (See related article in April 2005: vol. 79, issue 7, page 4055.)