CD40LG and B-cell chronic lymphocytic leukemia: While Herishanu et al. [6] and recently Krysov et al. [36] show that both IGHV mutated and IGHV unmutated CLL cells transcriptionally respond to BCR ligation in vitro, other studies reported that IGHV mutated CLL cells poorly respond to IgM stimulation, in contrast to IGHV unmutated CLL cells which do respond [12], [37]–[40].