approaching significancep ≈ 0.05
Expression and validation of biomarkers To validate biomarker expression patterns, Wilcoxon rank-sum tests revealed that in biomarker set 1, both BID and NDUFB6 were significantly downregulated in COPD and NSCLC with COPD groups compared to controls, while PRDX5 showed no significant difference in COPD (though approaching significance, p ≈ 0.05) but was significantly reduced in NSCLC with COPD ( Figures 9 A and 9B); for biomarker set 2, all five biomarkers exhibited significant differential expression in NSCLC versus controls ( Figure 9 C), whereas in NSCLC with COPD only UQCR11 reached significance with the other four biomarkers approaching the threshold ( p ≈ 0.05) ( Figure 9 D).