TLR9 and B-cell chronic lymphocytic leukemia: To recapitulate in vitro the inflammatory environment mimicking the biological situations occurring in vivo in the lymph nodes and to establish an experimental condition that induces chemoresistance [11], we stimulated primary CLL cells with the TLR9 ligand CpG for 4 h, and subsequently, we added increasing amounts of DMF; in a parallel set of experiments, the same samples were treated with DMF and concomitantly stimulated with CpG (see Fig. 5A, B for a schematic representation).