The monoclonal antibody CF1 recognizes human peripheral myelin protein 22 (PMP22). PMP22 is a 160 amino acid glycoprotein and contains four hydrophobic domains, presumably transmembrane regions. It is the second most abundant protein in the mammalian nervous system, but is, at least in rodents, also found in other tissues, including the liver and gut. Myelin protein zero (P0) is the most abundant protein in mammalian peripheral nerve myelin. An interaction between P0 and PMP22 has been detected in compact myelin. Defects in PMP22 have been related to Charcot-Marie-Tooth disease (CMT) and inflammatory demyelinating neuropathy (IDP). Immunization with PMP22 induces experimental auto-immune neuritis without central nervous inflammation. Therefore, PMP22 is considered as candidate auto-antigen in inflammatory diseases of the peripheral nervous system, including both acute and chronic inflammatory demyelinating polyradiculoneuropathy. Monoclonal antibody CF1 is crossreactive with Rhesus monkey PMP22.