CD40 and B-cell chronic lymphocytic leukemia: We and others have demonstrated that CD40 stimulation of CLL cells in vitro increased the expression of the anti‐apoptotic proteins Bcl‐XL, Bfl‐1, and Mcl‐1, which is consistent with the anti‐apoptotic profile of LN‐residing CLL cells in vivo [11, 12, 13, 14].