IFNA1 and systemic lupus erythematosus: ISG expression (IFN signature) was assessed in active j-NPSLE, inactive j-NPSLE, and j-SLE controls in 5, 7, and 5 patients, respectively, and median of IFN signature was not significantly different between active j-NPSLE patients and active j-SLE controls (median: 13 (n = 5) vs 19 (n = 5), p = 0.8968, data not shown).