Central nervous system-specific myelin protein that increase myelin genes expression during oligodendrocyte differentiation. Promotes oligodendrocyte terminal differentiation. In the CNS, enriched in the myelin paranodal and inner loop membranes, but not that of the PNS. Enriched in the leading edge of extending processes (PubMed:30837646). Expressed specifically in oligodendrocytes of the brain. Expression in the cerebellum increases dramatically after the first postnatal week (PubMed:18490449, PubMed:30837646). Selectively expressed in brain at P21, and not expressed in any other tissues tested including thymus, lung, heart, liver, spleen, kidney and testis. By leukemia inhibitory factor (LIF) and cAMP analogs. Suppressed in the presence of astrocytic or neural-stem-like differentiation factors such as bone morphotic protein (BMP) and fetal calf serum. Deficient mice are born the expected Mendelian ratio and have a normal body shape and weight. No obvious abnormalities in gross anatomy or major myelin protein components nor in the compartment of myelinated axons and oligodendrocyte maturation. Nevertheless, deficient mice display increased exploratory activity in a novel environment.