In contrast to the notion that IFN-I levels (as determined indirectly by quantification of IFN-I-induced chemokines and ISG expression) do not fluctuate with changes in SLE disease activity,52,54,55 we found that IFN-I activity levels correlate with changes in SLEDAI, anti-dsDNA, and C3, implying a potential disconnect between IFN-I levels and biomarkers attributed to the activity of IFN-I. This evidence concerns the gene C3 and systemic lupus erythematosus.