When using a BRD4 inhibitory “probe compound” (for definition, see Box 1), discovered at the Dana-Farber Cancer Institute, anti-leukemic effects across genomic AML subtypes were precisely recapitulated and found to largely depend on blocking the oncogenic transcription factor MYC (Zuber et al, 2011). This evidence concerns the gene BRD4 and acute myeloid leukemia.