Syncytin activation leads to a myriad of MS-associated pathology, such as pro-inflammatory profile in astrocytes, interleukin-1β (IL-1β) production, cellular protein oxidation, inhibition of oligodendrocyte maturation, myelin damage, and antagonization of remyelination up to neurobehavioral deficits (Antony et al., 2004). This evidence concerns the gene ERVW-1 and myeloid sarcoma.