CD40LG and chronic inflammatory demyelinating polyradiculoneuropathy: Routine labs do not show any hallmark of MMNCB, except a slight increase in muscle creatine kinase in two-thirds of patients or IgM monoclonal protein at immunofixation electrophoresis [72]; different from CIDP, the cerebrospinal fluid (CSF) protein level is elevated in only 30% of patients and did not reach a concentration over 1 g/l.