HBEGF and myeloid sarcoma: To identify the inflammatory mechanisms that trigger the upregulation of HB-EGF during acute phases of autoimmune CNS inflammation, we challenged naive astrocytes in vivo by intracerebroventricular (i.c.v.)injection of TNF-ɑ and IL-1β, two factors that have been linked to MS pathology and are potent inducers of astrocyte reactivity20,22,23.