The proper transmission of nerve signals along body nerves requires an insulation layer, named myelin sheath. To be efficient this sheath is designed to have a certain thickness and researchers have now discovered that proteins Dlg1 and PTEN interact to control the myelin sheath thickness. Their discovery improves our understanding of Charcot-Marie-Tooth neurodegenerative diseases and open a new avenue in the potential treatment of these incurable and debilitating diseases.