The most striking intergroup differences of HLA-C allele frequencies within the validation cohort were, again, overrepresentations of HLA-C*07 (OR = 1.82; 95% CI, 1.21–2.75; P = 0.004) and underrepresentations of HLA-C*12 (OR = 0.50; 95% CI, 0.26–0.97; P < 0.04) among the COPD participants. The gene discussed is HLA-C; the disease is chronic obstructive pulmonary disease.