SIRT1 and B-cell chronic lymphocytic leukemia: It can be speculated that this miR-132/SIRT1/TP53 axis represents the prevalent pathway activated in M CLL cells upon BCR triggering in vivo, while in UM CLL cells the activity of this pathway is overcome by additional pathways triggered by other types of antigens or other exogenous stimuli that may transmit more efficient pro-survival and/or proliferative signals to these cells (Figure 7) [28, 55–62].