BCL2 and cancer: The myeloid cell leukemia sequence 1 (MCL-1), one of the key anti-apoptotic members of the B cell lymphoma-2 (Bcl-2) protein family, is currently under development as potential molecules target of chemotherapies, due to the role of MCL-1 in promoting survival as well as in conferring chemotherapeutic resistance of many types of cancers [37–39].