Cell CycleCell AgingCell Cycle ProteinsCell Cycle CheckpointsG1 PhaseCyclin-Dependent Kinase Inhibitor p21Tumor Suppressor Protein p53Cell DivisionMitosisCell ProliferationCyclinsS PhaseCyclin-Dependent Kinase Inhibitor p16ApoptosisRetinoblastoma ProteinFibroblastsCells, CulturedDNA DamageSignal TransductionCell Line, TumorMediator ComplexG2 PhaseCell LineCyclin-Dependent Kinase Inhibitor p27Menstrual CycleG2 Phase Cell Cycle CheckpointsProtein-Serine-Threonine KinasesDNA-Binding ProteinsPhosphorylationInflammation MediatorsTelomereTumor Suppressor ProteinsNuclear ProteinsGene Expression RegulationMolecular Sequence DataTranscription FactorsAgingMutationRNA, MessengerG0 PhaseTime FactorsModels, BiologicalCyclin-Dependent Kinase 2Flow CytometryCDC2 Protein KinaseG1 Phase Cell Cycle CheckpointsCyclin D1TelomerasePlant LeavesDNA ReplicationCyclin ECyclin-Dependent Kinase 4Blotting, WesternCell NucleusDown-RegulationGenes, cdcTranscription, GeneticCyclin ARNA, Small Interferingbeta-GalactosidaseTumor Cells, CulturedCell SurvivalCell DifferentiationCyclin BHeLa CellsInterphaseBase SequenceRNA InterferencePhenotypeAmino Acid SequenceCDC2-CDC28 KinasesE2F Transcription FactorsReverse Transcriptase Polymerase Chain ReactionEstrous CycleSaccharomyces cerevisiaeDNAAging, PrematureGene Expression ProfilingUp-RegulationCell Transformation, NeoplasticTransfectionProtein Bindingcdc25 PhosphatasesGene Expression Regulation, NeoplasticPromoter Regions, GeneticHistonesGene ExpressionSaccharomyces cerevisiae ProteinsBromodeoxyuridineE2F1 Transcription FactorCyclin B1Mice, KnockoutRepressor ProteinsProtein KinasesEnzyme InhibitorsCyclin DProto-Oncogene ProteinsMice, Inbred C57BLCyclin-Dependent Kinase 6Antineoplastic Agents