Hitting their targets: an emerging picture of E2F and cell cycle control.

Understanding the role of transcription factors in governing cell-cycle progression in mammalian cells has been hindered until recently by a relative lack of genetic and genomic approaches. New approaches that harness the power of ChIP and combine this technique with DNA microarrays and bioinformatics have identified direct, physiological targets and have significantly altered our view of the E2F transcription factor that is known to play a role in regulation of cell-cycle progression. Further, the identification of additional E2F family members and factors that function in concert with E2F have considerably expanded our picture of the genetic programs that are governed by this essential regulatory factor.