To verify that miRNA expression profiling discerned differences between normal CD5-CD19+ B cells and CD5+CD19+CLL cells rather than between normal CD5-CD19+ and CD5+CD19+ B cells, control B cells from 4 different control donors were sorted into CD5- and CD5+ populations and RT-PCR analysis was performed. Here, CD19 is linked to B-cell chronic lymphocytic leukemia.