Decreasing histone acetylation with the HAT inhibitor C646 (Figure 1B), which preferentially targets the catalytic activity of CREBBP and the related acetyltransferase EP300 (also known as KAT3B), significantly reduced the proliferation of 8 out of 10 tested AML tissue culture cell lines (29). This evidence concerns the gene EP300 and acute myeloid leukemia.