HDACs/EZH2-IN-1 (Compound 22a) is a HDACs/EZH2 inhibitor ( EZH2 Y641N inhibition rate at 50 nM: 98%), with selective inhibition against HDAC1 and HDAC6 ( IC 50 : 0.23 μM and 0.07 μM, respectively). HDACs/EZH2-IN-1 exerts a antiproliferative effect on diffuse large B-cell lymphoma cells harboring an EZH2 mutation and on various acute myeloid leukemia cells. HDACs/EZH2-IN-1 has the ability to induce cell differentiation and Apoptosis.