Although the target antigen in MS is still unknown, proteins within the myelin sheath, such as: RAS guanyl releasing protein-2 (RASGRP2), glial cell adhesion molecule (GlialCAM), myelin phosphatide protein (MBP), myelin oligodendrocyte glycoprotein (MOG) and proteolipid protein (PLP) seem to be relevant targets of the autoimmune response in MS [18–21]. The gene discussed is RASGRP2; the disease is myeloid sarcoma.