TLR9 and B-cell chronic lymphocytic leukemia: Already before the discovery of TLR9 as the cognate receptor for unmethylated-CpG-oligonucleotides,50 these immunostimulatory agents have been used to stimulate leukemic CLL cells for immunotherapeutic strategies.51 Therefore, it was assumed, and soon confirmed, that CLL cells express functional TLR9, similar to normal B lymphocytes.52,53 However, only recently the full expression pattern of TLR was assessed in CLL samples by different groups.54–56