Regarding IL-21, the SLE-A group exhibited significantly higher IL-21 levels than the SLE-nA (78.08 ± 23.18 vs. 39.56 ± 19.57, p<0.001) and HC groups (78.08 ± 23.18 vs. 26.45 ± 15.70, p<0.001). The gene discussed is IL21; the disease is systemic lupus erythematosus.