IL18 and chronic obstructive pulmonary disease: The positive association of IL-18 on COPD (OR: 1.31, 95%CI: 1.21 to 1.42, p < 0.001), and the inverse associations of IL-18 on FEV1 (−0.061, 95%CI: −0.071 to −0.051, p < 0.001) and FVC (−0.079, 95%CI: −0.093 to −0.065, p < 0.001), were replicated in an observational analysis in the UK Biobank.