CD40LG and B-cell chronic lymphocytic leukemia: As shown in Figure 4A–4B, SIRT1 protein levels were significantly reduced (mean fold change 0.87±0.06; P = 0.001) upon anti-IgM stimulation of CLL cells (5 UM CLL and 4 M CLL), with similar decrements when comparing UM and M CLL samples (P = 0.41).