Generally, cryoglobulins are common, and they have been classified in into three types: Type 1 (simple) includes any of monoclonal IgG, IgM, IgA, or Bence Jones protein/monoclonal free light chains that have been associated with Waldenström ’s macroglobulinemia, multiple myeloma, monoclonal gammopathy associated with lymphoproliferative disorder, and light chain disease. The gene discussed is CD40LG; the disease is plasma cell myeloma.