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. 2020 May 15;15:1049–1059. doi: 10.2147/COPD.S234464

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© 2020 Gao et al.

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The workflow of the study design.

Abbreviations: VDBP, vitamin D binding protein; GC, VDBP also known as group-specific component-globulin; GC1F, rs7041-T/rs4588-C; GC1S, rs7041-G/rs4588-C; GC2, rs7041-T/rs4588-A; COPD, chronic obstructive pulmonary disease; Smokers, smokers without COPD.