Zero, also known as myelin protein zero (MPZ) is a Type 1 integral membrane glycoprotein that mediates adhesion of spiraling wraps of the myelin sheath in order to ensure stable synaptic transmission. Zero protein encompasses approximately 50% of total protein in the sheath scaffolding in contribution to structural integrity of peripheral myelin. Zero guides the compact myelin wrapping process through glycine zipper packing interface-dependent dimer and tetramer formation. Mutations (e.g. G134R) can abrogate multimer formation, cause demyelinating neuropathies, and are known to contribute to conditions that include Charcot-Marie-Tooth disease. Zero cytoplasmic domain undergoes serine and tyrosine phosphorylation, which appears to be prevalent during peak nerve myelination. Zero transcript is moderate in brain, abundant in thymus and most abundant in white matter of the CNS.