May dephosphorylate MAPK13, ATF2, ERBB3, PDGFRB and SNX6 (By similarity). May play a role in the regulation of oligodendrocyte differentiation (PubMed:22792334). May play a role in the regulation of myelin formation (By similarity). Involved in the regulation of Erk1/2 phosphorylation in Schwann cells; the signaling may be linked to the regulation of myelination (By similarity). H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Isoform 1 is expressed in testis; predominantly in developing spermatocytes (at protein level) (PubMed:15138252). Isoform 2 is highly expressed in testis (PubMed:11432789). Expressed in spinal cord and specifically in oligodendroglial cells (PubMed:27532821). Expressed in embryonic brain cortex; down-regulated in mice with experimental autoimmune encephalomyelitis (EAE) (PubMed:22792334). Expression increases during oligodendrocyte differentiation. Detected in spinal cord in late fetal (18.5 dpc) and early postnatal (P3 and P7) stages. Expression decreases in later postnatal development (P14 and P30). Down-regulated by nerve injury. Inactive. Lacks the active site. Belongs to the protein-tyrosine phosphatase family. Non-receptor class dual specificity subfamily.