CREB1 and cancer: The cyclic‐AMP (cAMP)‐response element binding protein (CREB) is a nuclear transcription factor belonging to a family of basic leucine zipper (bZIP)‐containing transcription factors that serves a variety of biological functions including cellular proliferation and differentiation.26, 27, 28 Recently, accumulating evidence has revealed that CREB participates in the immortalization and transformation of cancer cells.