BCL2L1 and B-cell chronic lymphocytic leukemia: Our results with patient samples extend and confirm our findings in the human cancer cell lines that secondary survival factors dampen the full impact of targeting the dominant survival factor in diverse hematological malignancies: BCL2 or BCLxL for MCL1i in myeloma (Fig. 6A) and in the case of CLL, MCL1 for venetoclax (Fig. 6B).