CREB1 and neoplasm: PGE2 stimulates prostaglandin E2 receptor to activate MAPK/ERK (also known as the Ras-Raf-MEK-ERK) and PI3K/Akt pathways, and activates multiple transcription factors, such as AP-1 and CREB, which promote the expression of Cyclin D1, VEGF, AREG, Bcl-2, etc., and result in tumor cell proliferation, survival, antiapoptosis and angiogenesis ([36-39]; Figure 7).