BCL2 and B-cell chronic lymphocytic leukemia: Within B-cell tumors, BCL-2 dysregulation commonly arises from genetic abnormalities, such as the t(14;18)(q32;q21) translocation in follicular lymphoma (FL) or focal deletion of chromosome 13 (del[13q14]) that leads to loss of negative regulatory miRNA-15a/16-1 of BCL-2 in CLL.