The serum concentration of IL-32 was negatively correlated with FEV1/FVC (correlation coefficient = − 0.356, p = 0.001; F = 11.207, p = 0.001; T = − 3.348, p = 0.001; the regression equation = ^Y = 0.593–0.096X) (Fig. 2A–C; Table 2) and FEV1% predicted (Correlation coefficient = − 0.300, p = 0.001; F = 11.295, p = 0.001; T = − 3.361, p = 0.001; the regression equation = ^Y = 0.634–0.062X) (Fig. 2D–F; Table 2) in stable COPD patients. This evidence concerns the gene IL32 and chronic obstructive pulmonary disease.