Univariate linear regression found that S100A4 was positively correlated with S1P in all cases (β = 0.157, 95% CI: 0.352~2.726) and COPD patients (β = 0.314, 95% CI: 4.311~14.518) (Table 3). This evidence concerns the gene S100A4 and chronic obstructive pulmonary disease.