Frequency distributions of the combined genotypes between CWP cases and controls.

aVariant homozygote/Heterozygote/Wild type homozygote;
bAdjusted for age, exposure years, pack-years smoked, and occupation.

a. 变异型纯合子（homozygote）/杂合子（heterozygote）/野生型（wild type）纯合子；b. 已针对年龄、暴露年限、吸烟包年数（pack-years smoked）以及职业进行校正。