CNTNAP1 and chronic inflammatory demyelinating polyradiculoneuropathy: We compared the clinical features and responses to treatments of patients with IgG4 antibodies against Nfasc155, CNTN1, or Caspr1 with those of 64 randomly selected patients with CIDP who were negative for antibodies against Nfasc155, Nfasc140/186, CNTN1, or Caspr1.