IFNB1 and myeloid sarcoma: Clinical studies in MS patients treated with recombinant interferon-β (IFN-β), which moderately reduces relapse rate, disability progression and MRI disease activity [9], seemed to support this hypothesis: IFN-β therapy increased sVCAM-1 serum levels, which correlated with a reduction of gadolinium (Gd)-enhancing MRI brain lesions, indicating less inflammatory disease activity at the BBB [12, 20, 38].