Mediation analysis results using data from a lung cancer genome-wide association study.*

CI: Confidence interval*Both daily smoking quantity and COPD were used as the mediators in the multiple-mediator model. The 95% CIs for the indirect effects were estimated based on 10,000 bootstraps. Includes the indirect effect through smoking (i.e., IE1 = a1b1), the indirect effect through COPD (i.e., IE2 = a2b2), the three-path indirect effect through smoking and COPD (i.e., IE3 = a1db2), the total indirect effect (i.e., IEt = IE1+IE2+IE3), the total effect (i.e., TE = IEt+c′), and the percentages of the SNP-lung cancer association explained by different paths (i.e., PM1 = IE1/TE, PM2 = IE2/TE, PM3 = IE3/TE, and PMt = IEt/TE).