PMP22 and Charcot-Marie-Tooth disease: Furthermore, many genes related to synthesizing structural proteins involved in myelination include (PMP22, MPZ), proteins of axonal transport (NEFL), genes involved in Schwann cell differentiation (EGR2), gene controlling members of signal transduction pathways (NDGR1) and genes regulating mitochondrial function (MFN2) have been identified to be responsible for the appearance and progression of CMT [14,15].