IL32 and chronic obstructive pulmonary disease: The stepwise regression of multiple linear showed that patient's COPD grading (p = 0.001; 95% CI = 6.63 to 26.61), clinical medical history (p = 0.023; 95% CI = 0.03 to 3.52) and FEV1/FVC (p = 0.001; 95% CI = − 175.16 to − 44.93) seemed to affect the serum IL-32 concentration (Fig. 3A–C; Table 3).