The serum IL-17 level was significantly higher in SLE patients than in HC [median (IQR): 36.3 (17.36–105.92) vs. 29.47 (15.16–62.17) pg/mL, p = 0.009]. There was an association between serum IL-17 levels and active nephritis (p = 0.01). Serum IL-17 levels were not associated with disease activity (p = 0.32), cumulative damage (p = 0.34), or medication use (p = 0.63). The gene discussed is IL17A; the disease is nephritis.