BRD4 and cancer: JQ1 and iBET-151 are shown to bind to the BRD4 bromodomains and displace the BRD4-P-TEFb complex from acetylated chromatin to inhibit MYC transcription, which in turn induces differentiation and growth arrest of cancer cells (e.g., acute myeloid leukemia, multiple myeloma, and Burkitt's lymphoma) that are addicted to MYC (Filippakopoulos and Knapp, 2014; Shi and Vakoc, 2014).