MCL1 and acute myeloid leukemia: We and others have reported that MCL-1, a major resistance factor for BCL-2 inhibition, is frequently induced in VEN-resistant AML cells [20–22] and that co-inhibition of BCL-2 and MCL-1 is highly synergistic, both in vitro and in vivo, against various malignant cells, including AML cells and stem/progenitor cells, that have intrinsic or acquired resistance to VEN [18, 23–28].