MCL1 and leukemia: To further evaluate the impact of BCL-2/MCL-1 inhibition in combination with CalPegA on leukemia cell growth in vivo, we utilized a previously established [5] luciferase-expressing patient-derived xenograft (PDX) model from primary cells that were cryopreserved from a patient with relapsed complex karyotype AML (AML45-luc).