The molecular composition of the node of Ranvier has been characterized in the last 20 years (1–4), and autoantibodies that target these proteins, namely neurofascin, contactin1, and Caspr have been identified in chronic inflammatory demyelinating polyneuropathy (CIDP) in the past 6 years (5, 6). The gene discussed is CNTNAP1; the disease is chronic inflammatory demyelinating polyradiculoneuropathy.