Various studies now point to the role of cooperative transcription factor interactions as a mechanism to achieve the necessary specificity in promoter recognition. An example can be seen in the action of E2F proteins where interactions with other transcription factors not only provides this general specificity but also the specificity that distinguishes function of the individual E2F proteins. This includes both the activation and repression functions of E2Fs and has now also been extended to the control of G(2)/M regulated genes in addition to the G(1)/S E2F targets. These studies further highlight events linking the control of G(1)/S genes with G(2)/M, providing a mechanism to achieve the temporal control of gene expression as cells move through the cell cycle.