Venetoclax (ABT-199), a highly selective inhibitor of Bcl-2, is the first FDA-approved Bcl-2 antagonist for the treatment of various hematologic malignancies including chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) as a single agent, and for acute myeloid leukemia (AML) in combination with chemotherapy [57]. Here, BCL2 is linked to B-cell chronic lymphocytic leukemia.