Cover photograph (Copyright © 2006, American Society for Microbiology. All Rights Reserved.): Pin1-induced centrosome overduplication results in the division of one cell into three cells. Phosphorylation-specific isomerase Pin1 plays a critical role in regulating centrosome duplication, and its deregulation can induce centrosome amplification, chromosome instability, and oncogenesis. (See related article on p. 1463.)