We anticipate that our in vitro findings about BTEC formation, expansion of T-bet+CXCR3+ B cells, hyperreactive B and T cell AP,3 the involved genetic and environmental risk factors,4 and how these translate into MS pathomechanisms not only may guide further studies of the genetic and environmental contributions but will also be instrumental for testing existing and developing new treatments for MS. The gene discussed is CXCR3; the disease is myeloid sarcoma.