The mRNA expression levels of OPG in both AF and NP cells were significantly upregulated by treatment with IL-1β at 0.1 ng/mL (relative expression (vs. control): AF 2.92 ± 0.39; NP 6.35 ± 1.36; p < 0.01, respectively), at 1.0 ng/mL (relative expression (vs. control): AF 3.11 ± 0.34; NP 6.52 ± 1.42; p < 0.01, respectively), and at 10 ng/mL (relative expression (vs. control): AF 3.17 ± 0.34, p < 0.01; NP 6.00 ± 1.53, p < 0.05) (Fig. 3e, f). The gene discussed is TNFRSF11B; the disease is atrial fibrillation.