CUDC-907 has exhibited antitumor activity in various hematological malignancies, including diffuse large B-cell lymphoma, AML, CLL, and multiple myeloma.45–48 In this work, we demonstrated a strong anti-proliferative effect of this compound on primary BM cells from BCP-ALL patients or PDX models harboring MEF2D fusion genes. Here, MEF2D is linked to acute lymphoblastic leukemia.