Cover photograph (Copyright © 2007, American Society for Microbiology. All Rights Reserved.): The image on the left shows green fluorescent protein expression driven by eye-specific enhancer Dap-HB, which controls expression of the Drosophila cdk inhibitor Dacapo during fly eye development. Staining with antibodies against the neuronal marker Elav (upper right) and the R2 and R5 photoreceptor marker Rough (lower right) indicates that Dap-HB was active in R2 and R5 photoreceptor neurons. (See related article on p. 2987.)