APEX1 and myeloid sarcoma: Finally, Apex1 (h2 = 0.28), apurinic/apyrimidinic endodeoxyribonuclease 1, is an essential DNA repair enzyme, which has been shown to have a role in preserving the survival of neurons and oligodendrocytes after ischemic injury [100]; therefore, Apex1 DNA repair after oxidative damage could be considered as a protective agent in gray- and white-matter maintenance and consequently against MS onset [101].