||CREBBP is ubiquitously expressed and is involved in the transcriptional coactivation of many different transcription factors. First isolated as a nuclear protein that binds to cAMP-response element binding protein (CREB， CREBBP is now known to play critical roles in embryonic development, growth control, and homeostasis by coupling chromatin remodeling to transcription factor recognition. CREB binding protein has intrinsic histone acetyltransferase activity and also acts as a scaffold to stabilize additional protein interactions with the transcription complex. CREB binding protein acetylates both histone and non-histone proteins. CREB binding protein shares regions of very high sequence similarity with protein p300 in its bromodomain, cysteine-histidine-rich regions, and histone acetyltransferase domain. Mutations in CREBBP cause Rubinstein-Taybi syndrome (RTS). Chromosomal translocations involving CREBBP have been associated with acute myeloid leukemia. Alternative splicing results in multiple transcript variants encoding different isoforms.