The PI3K inhibitor CAL-101 also interferes with survival effects of CD40L, tumor necrosis factor-α and fibronectin in CLL cells and BTK is required for Toll-like receptor signaling.64 Thus, the contribution of specific BCR signaling inhibition to the clinical efficacy of these agents remains unclear as yet. Here, CD40LG is linked to B-cell chronic lymphocytic leukemia.