TLR9 and B-cell chronic lymphocytic leukemia: Unmutated IGHV CLL has a greater capacity to signal through the BCR upon antigen stimulation; accordingly, stimulation of CLL cells using the immunostimulatory cytosine–phosphate–guanosine (CpG), an agonist of the Toll-Like Receptor 9 (TLR9), increased the expression of 21 miRNAs in IGHV unmutated cells.