BCL2 and B-cell chronic lymphocytic leukemia: miRNA deregulation in tumor biology was first observed in miRNA-15a and miRNA-16-1 within locus 13q14, both of the two miRNAs which targeted B-cell lymphoma 2 (Bcl-2) mRNA were deleted or downregulated in most majority of the chronic lymphocytic leukemia (CLL) cases, resulting in tumorigenesis by reducing apoptotic activities [11].