Glial cells are cells that support nerve cells. Schwann cells wrap around the axon to form the myelin sheath. Schwann cells are involved in many important aspects of peripheral nerve biology; the conduction of nervous impulses along axons, nerve development and regeneration, trophic support for neurons, production of the nerve extracellular matrix and presentation of antigens to T-lymphocytes. Charcot-Marie-Tooth disease (CMT), Guillain-Barre syndrome (GBS), schwannomatosis and chronic inflammatory demyelinating polyneuropathy (CIDP) are all neuropathies involving Schwann cells.