MYD88 and B-cell chronic lymphocytic leukemia: Finally, activating mutations in myeloid differentiation primary response gene 88 (MYD88) are found in approximately 3% of CLL cases; these mutations lead to constitutive signaling down-stream of Toll-like receptors (TLRs) and increased expression of the T-cell-attracting chemokines CCL3 and CCL4 [14].