IRF8 and myeloid sarcoma: In microglia nodules in MS, genes indicating immunoglobulin (Ig) signaling were upregulated as compared to MS non-nodular NAWM: HLA-DMA, HLA-DPB1, HLA-DMB, HLA-DRB1, HLA-DRB5, none after correction; compared to microglia nodules in stroke: HLA-DRB5 (also after correction) and of cytokine signaling, specifically interferon (IFN)y and TNF (compared to MS non-nodular NAWM: IRF8, CD84, LRRK2, FADD, LPL, TLR2, EGR1, IL18, after correction IL18; compared to microglia nodules in stroke: IFNAR2, also after correction).