As a step toward unraveling mechanism(s) for reduced BCL2 protein during cycling, we tested for miR15a/miR16-1 involvement in the decline by segregating assessed CLL populations into cohorts based on the presence of del(13q), which removes coding regions for miR15a/miR16-1 [6-9] (Figure 4). This evidence concerns the gene BCL2 and B-cell chronic lymphocytic leukemia.