PSMB9 and myeloid sarcoma: LMP2 mRNA was found in EBV-infected circulating B lymphocytes of both MS and healthy individuals (Tierney et al., 1994; Serafini et al., 2007), but, importantly, LMP2A mRNA was also found in brain-infiltrating B lymphocytes of MS patients (Serafini et al., 2010).