PMP22 and Charcot-Marie-Tooth disease: Duplication and deletion of the PMP22 gene is associated with Charcot-Marie-Tooth disease (CMT) and Hereditary Neuropathy with Pressure Palsies (HNPP) 15, 16, and several studies have shown that PMP22 regulates tumor development, metastasis, and invasion in different cancers in addition to its functions in neurodevelopmental and neurological disorders17-28, 30.