CCND1 and cancer: For example, various kinds of transcriptional factors of cyclin D1, such as activator protein-1 (AP-1),7, 8 Sp1,9 nuclear factor-κB,9 CREB,10 signal transducer and activator of transcription factor 3 (STAT3),11, 12 STAT513, 14 and T-cell factor (TCF)/lymphoid enhancer factor15, 16 are constitutively activated in cancer cells.