Fig. 3

MMP-12 gene polymorphism −82 A-to-G SNP impact on MMP-12 protein level in serum of COPD patients and healthy control groups (A, allele impact on MMP-12 protein level; B, genotype impact on MMP-12 protein level). Legend: COPD, patients with chronic obstructive pulmonary disease; CTR – controls; data expressed as medians (25 and 75% percentiles); no significant difference in mean MMP-12 protein levels between carriers with different − 82 A > G alleles/genotypes in one-way ANOVA test, Tuckey post-hoc test were not conducted