EGF and myeloid sarcoma: If MS demyelination is likely caused by a local deficiency in myelinotrophic molecules combined with a local ODC paucity, a local ODC differentiation block, and a local excess of remyelination-impeding agents, it is therefore of primary importance to redress this imbalance by stimulating the search for a means of remyelination: findings showing EGF-, NRG-, and PrPC-deficiency in MS SC support this need (Viehover et al. 2001; Scalabrino et al. 2010, 2015).