As shown in Table 2, univariate linear regression indicated that serum S100A4 was negatively associated with FEV1% (β = −0.470, 95% CI: -2.079~-1.044), FEV1/FVC% (β = −0.252, 95% CI: -0.810~0.156), FEV1 (β = −0.405, 95% CI: -0.041~-0.018), and FVC (β = −0.348, 95% CI: -0.048~-0.017) in COPD patients. This evidence concerns the gene S100A4 and chronic obstructive pulmonary disease.