TLR9 and mantle cell lymphoma: Investigators evaluated MCL(mantle cell lymphoma) and CLL cells which were treated with microenvironmental agonists such as IL-10, CD40L and especially the Toll receptor 9 (TLR9)-specific agonist cytosine guanine-oligodeoxynucleotides (CpG-ODNs), and observed a significant increase in the activation of the NF-κB signaling pathway, resulting in drug resistance accompanied by increased expression of BCL-XL and MCL-1 (30).