Cyclin E2: ProductsCyclin E2 (CCNE2) is an approximately 45-50 kDa protein that associates with the kinase Cdk2. This complex phosphorylates multiple substrates involved in regulation of cell cycle progression and the initiation of DNA replication. Cyclin E2 is required for G1/S phase progression and cell cycle reentry from G0 phase. Cyclin E2 most highly expressed in testis, thymus, and brain and is frequently upregulated in cancer. Cyclin E2 contains two cyclin box folds (aa 141-231 and aa 241-361). An alternate splice form lacks 45 amino acids within the first cyclin box fold.