IL1B and myeloid sarcoma: To assess whether inflammatory mediators that are abundantly present in MS lesions contribute to fibronectin aggregation, we applied a reductionist approach and exposed primary rat astrocytes to pro-inflammatory cytokines IL1β, IFNγ and TNFα, and TLR2, TLR3, and TLR4 agonists zymosan, Poly(I:C) and LPS, respectively.