Antibodies to cell adhesion molecules of the paranodal complex, neurofascin-155 (Nfasc155), contactin-1 (CNTN1), and contactin-associated protein 1 (Caspr1), and to nodal neurofascin-140/186 (Nfasc140/186) have been identified in various percentages of patients with CIDP, with IgG4 being the predominant isotype of these antibodies.2, –, 8 Moreover, IgG4-seropositive patients show specific clinical features and a poor response to IVIG. This evidence concerns the gene CNTNAP1 and chronic inflammatory demyelinating polyradiculoneuropathy.