PLP1 and myeloid sarcoma: Since demyelination is a key feature of MS neuropathology, it has been hypothesized that antigens derived from myelin protein such as myelin basic protein (MBP), myelin-associated glycoprotein (MAG), myelin proteolipid protein (PLP), and myelin and oligodendrocyte glycoprotein (MOG) are the primary target of attack of the immune system.