Waldenström macroglobulinemia (WM) is a rare, indolent B-cell lymphoproliferative disorder, specifically a lymphoplasmacytic lymphoma, characterized by bone marrow infiltration by clonal lymphoplasmacytic cells and the production of monoclonal immunoglobulin M (IgM) [1,2]. Here, CD40LG is linked to Waldenstrom macroglobulinemia.