BCL2 and B-cell chronic lymphocytic leukemia: The introduction of small molecule inhibitors, such as Bruton tyrosine kinase (BTK) [7–10], phosphoinositide 3-kinase (PI3K) [11], or B-cell Lymphoma 2 (BCL-2) [12, 13], has changed the treatment paradigm by providing even more effective therapeutic options for CLL patients.