Given the potential overlap with CIDP, it would be prudent to include patients with the typical phenotype, with at least 1 nerve exhibiting demyelinating range abnormalities, with an IgM monoclonal gammopathy (MGUS or Waldenström's macroglobulinemia), and highly elevated anti-MAG antibodies of ≥7,500 using the Buhlmann assay or ≥1:25,600 in the dilutional assay, as previously discussed. Here, CD40LG is linked to Waldenstrom macroglobulinemia.