The BET bromodomain inhibitors EP11313 and EP11336, impair the viability of AML blasts in vitro and have synergistic activity when combined with the retinoid all-trans -retinoic acid (AtRA). MV-411 cells were incubated with the indicated concentrations of EP11313, EP11336 and AtRA for 48 hours. Cell viability was measured using a bioluminescence assay (CellTiter-Glo¨, left) and induction of caspase 3, was measured by FACS (right). Growth inhibition (GI) in OCI-AML3 cells was calculated using linear extrapolation (top).