BCL2L1 and B-cell chronic lymphocytic leukemia: The main regulators of apoptosis include both the pro-survival and pro-apoptotic proteins of the Bcl-2 (B-cell CLL/lymphoma 2) family such as Bcl-2 (B-cell lymphoma 2), Bcl-x (BCL2 like 1) with Bcl-xL (B-cell lymphoma extra-large) and Bax (Bcl-2-associated X protein) as well as the caspases.