predicted correctly the four HDACs but not BRD4, while SwissTargetPrediction predicted correctly only HDACs 1, 6 and 8. Although a more exhaustive external validation is needed, these results suggests that epigenetic targets with large amounts of chemogenomic data associated (such as HDACs) are generally well represented in current target prediction tools, while those with fewer data are not well covered. Moreover, it should be noted that the known epigenetic targets were not always among the top predictions for the available tools. For instance, HDACs 3, 6 and 8 were ranked 12, 13 and 15 by SEA, and HDACs 1, 6 and 8 from SwissTargetPrediction were ranked in positions 42, 43 and 44, so in a practical application, these targets would be hardly prioritized. Although the experimental validation of the predictions from all models would be needed to provide better means of comparison, these findings reinforce the potential usefulness of a tool focused on epigenetic targets for medicinal chemistry applications in drug discovery.