Conversely, serum BAFF levels were significantly higher in patients with CTD-ILD (n = 33; 2.0 (0.6-16.7) ng•mL−1) than in patients with CFIP (n = 19; 1.0 (0.3-1.9) ng•mL−1, p = 0.0074) or healthy controls (n = 26; 0.6 (0.5-0.9) ng•mL−1, p < 0.0001). The gene discussed is TNFSF13B; the disease is interstitial lung disease.