Acetylation of lysine residues is a post-translational modification with broad relevance to cellular signaling and disease biology. Enzymes that ‘write’ (histone acetyltransferases, HATs) and ‘erase’ (histone deacetylases, HDACs) acetylation sites are an area of extensive research in current drug development. The principal readers of ɛ-N-acetyl lysine (Kac) marks are Bromo and extra terminal (BET) proteins (BRD2, BRD3, BRD4 and BRDT), which are in turn transcriptional regulators required for efficient expression of several growth promoting and anti-apoptotic genes as well as for cell cycle progression[1]. Moreover, they have an important role in the targeting of chromatin-modifying enzymes to specific sites. Often they act with other protein-interaction modules to guarantee a high level of targeting specificity for these essential enzymes[2].