TLR9 and B-cell chronic lymphocytic leukemia: Interestingly, CLL cells were slightly more susceptible to BA-impaired growth when un-stimulated, compared to when they were stimulated with CpG-2006 oligonucleotides (CpG-ODN), a toll-like receptor 9 agonist commonly used to mimic TME immunostimulatory signals [27] (Figure 3).