"Progression from G1 phase into the S phase of the eukaryotic cell cycle requires activation of a large family of G1-specific genes. Although the conservation of cell cycle regulatory networks between yeast and metazoans has long been recognized, a yeast repressor of G1-specific gene expression analogous to the metazoan Rb tumor supressor has remained elusive. Articles by de Bruin et al. (pp. 887898) and Costanzo et al. (pp.899913) in this issue of Cell describe Whi5, an inhibitor of G1-specific transcription in yeast that, like Rb, is antagonized by G1 cyclin-dependent protein kinases. (Cover micrographs by D.J. Clarke and J.F. Gimenez-Abian. Concept and art by M. Giesbertz, M. Pique, and C. Wittenberg.)"