Cover photograph (Copyright © 2000, American Society for Microbiology. All rights reserved.): Differentiation of 3T3-L1 adipocytes was induced by expression of a constitutively active CREB, composed of the viral VP16 transactivation domain linked to the CREB DNA-binding domain. Ten days later, the cells were stained with Oil Red O to visualize triacylglycerol vesicles, counterstained with hematoxylin, and visualized by light microscopy. This image demonstrates that CREB activation is likely to play a key role in initiating the adipogenic cascade. (See related article in February 2000, issue 3: vol. 20, p. 1008-1020.)