There was a statistically significant graded increase of serum IL‐6 level from the NSR to the SCAF (vs NSR: 6.8 ± 3.9 vs 4.0 ± 2.2 pg/mL, P = .03), and chronic AF subgroups (vs NSR: 9.3 ± 6.5 vs 4.0 ± 2.2 pg/mL, P < .01; vs SCAF: 9.3 ± 6.5 vs 6.8 ± 3.9, P = .05) of atrial fibrillation. The gene discussed is IL6; the disease is atrial fibrillation.