Two classes of BET inhibitors (BETI), the benzodiazapenes and quinolones, have been recently shown to exhibit significant in vitro and in vivo antitumor activity in multiple tumor types including lung cancer, prostate cancer, neuroblastoma and various hematological malignancies including B-cell lymphoma.3, 4, 5, 6, 7, 8, 9, 10, 11 Excitingly, recent data from a phase I trial of the BET inhibitor OTX-015 displayed potent single-agent antileukemic activity with minimum toxicity.12 This evidence concerns the gene DNER and prostate carcinoma.