CPI203 is a thienodiazepine derivative11 that decreased Myc mRNA and reduced leukemia burden in a T-cell acute lymphoblastic leukemia mouse model.12 Extensive studies of the related small molecule (+)−JQ1 in leukemia and lymphoma have shown that this BET protein bromodomain inhibitor (BETi) achieved antitumor activity through suppression of MYC.13,14 The ability of BETi to reduce expression of MYC highlights the promise of this therapeutic strategy to target MYC. This evidence concerns the gene MYC and T-cell acute lymphoblastic leukemia.