BRD4 and acute myeloid leukemia: The concept of dual Plk1 and BRD4 inhibition may be interesting in light of ongoing trials with epigenetic modulators.73 The histone deacteylase inhibitor valproic acid has been shown to upregulate trimethylation of histone H3 lysine 27 in AML cells,74 and may be an interesting drug for volasertib combination therapy.