KMT2D and acute myeloid leukemia: An in vitro assay for histone methyltransferase/acetyltransferase activity showed that piribedil had little effect on the activity of MLL4 (IC50 > 100 μM) and less potent effects on EZH2, NSD2, PRMT4, p300, and SMYD3, suggesting that piribedil specifically targets MLL1 as opposed to other SET domain-containing enzymes and effectively inhibits MLL-rearranged AML proliferation by interfering with the MLL1–WDR5 interaction [205].