Wiktionary
myelin protein zero
n. (context protein English) the major structural protein of the peripheral myelin sheath
Wikipedia
Myelin protein zero
Myelin protein zero (P0, MPZ) is a glycoprotein which in humans is encoded by the MPZ gene. P0 is a major structural component of the myelin sheath, and its deficiency due to various mutations in the MPZ gene is associated with Charcot–Marie–Tooth disease and Dejerine–Sottas disease.