The consensus group at the Second International Workshop on Waldenström's macroglobulinemia (WM) in 2002 redefined WM as a distinct clinicopathologic entity characterized by bone marrow infiltration by lymphoplasmacytic lymphoma (LPL) and immunoglobulin M (IgM) monoclonal gammopathy [1]. The gene discussed is CD40LG; the disease is monoclonal gammopathy.