The chemically synthesized CBP/p300 bromodomain inhibitor GNE-049 displays effective suppression of both CBP (IC50 = 1.1 nM) and p300 (IC50 = 2.3 nM), and exhibits strong efficacy in repressing the expression of oncogenes, such as MYC (EC50 = 14 nM), in leukaemia cells 97. This evidence concerns the gene CREBBP and leukemia.