IFNB1 and myeloid sarcoma: Reference datasets for the IFNB1 signature from multiple sclerosis (MS) patients chronically treated with recombinant IFNB1 compared to untreated MS patients41 (MS-IFNB1) and the IFNA2 signature derived from PBMC of hepatitis C patients treated with IFNA242 (HepC-IFNA2) were employed to interrogate the nature of the SLE IGS in greater detail.