In contrast, IgG2 (unadjusted HR = 1.36; 95% CI = 0.79–2.33) and IgG3 deficiency (adjusted HR = 1.27; 95% CI = 0.51–3.15) were not associated with increased risk of mortality in patients with COPD. The gene discussed is IGHG3; the disease is chronic obstructive pulmonary disease.