CXCL10 and systemic lupus erythematosus: Studies investigating the correlation between ISG score or surrogate markers of type I IFN (e.g. CXCL10, galectin-9) and disease activity in SLE patients have yielded inconsistent results, with some showing a correlation with ISG score or IFN surrogates [44] and others finding no such association [39, 40].