Features less consistent with MGNS (asymmetry, motor-predominant, rapidly progressive, length independent, negative MAG-antibodies, or axonal nerve conduction) should prompt a work-up for other diseases that may be associated with an IgM paraprotein and peripheral neuropathy, such as AL amyloidosis, POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes), cryoglobulinemia, and Bing-Neel syndrome (8). Here, CD40LG is linked to cryoglobulinemia.