In the CYP27B1 rs4646536 SNP, the genotypic and dominant models showed that the presence of the AA genotype was associated with a higher risk of developing COPD (p < 0.001, OR = 2.93, 95% CI = 1.60-5.76, AA vs. GG, and p < 0.001, OR = 1.87, 95% CI = 1.29-2.73, AA vs. G; Table 2). The gene discussed is CYP27B1; the disease is chronic obstructive pulmonary disease.