IFNB1 and Duchenne muscular dystrophy: Relapse-free F-MS showed a significantly higher frequency of CD56+ T cells (the mean frequency, 10.8%) compared with HS (2.5%, p < 0.0001), IFN-β-treated patients (2.2%, p < 0.0001), and patients not treated with DMD (3.9%, p = 0.0055) in remission (Fig. 1a,b).