CXCL13 and systemic lupus erythematosus: Notably, CXCL13 not only showed significant differences between HC and SLE patients (HC vs. non-LN: 26.03 ± 1.55 vs. 63.84 ± 5.97 pg/ml, P < 0.001; HC vs. LN: 26.03 ± 1.55 vs. 86.07 ± 9.02 pg/ml, P < 0.001), which also showed a significant difference between non-LN patients and LN patients (SLE vs. LN: 63.84 ± 5.97 vs. 86.07 ± 9.02 pg/ml, P-adj < 0.01) (Figure 4A).