The CBP/p300 HAT inhibitor C646 down-regulates oncogene expression, reduces acute myeloid leukemia cell clonogenic potential, and induces acute myeloid leukemia cell cycle arrest, apoptosis and melanoma and non-small cell lung cancer cell growth arrest 71, 74, 89 (Table 2). This evidence concerns the gene CREBBP and non-small cell lung carcinoma.