PTPRZ1 and multiple sclerosis: The 2 that were up-regulated, were only altered in the OB: Ptprz1 (protein tyrosine phosphatase, receptor-type, Z polypeptide 1) is expressed in the remyelinating oligodendrocytes of multiple sclerosis lesions [46]; and Pmp22 (peripheral myelin protein 22) is a component of myelin.