To assess the effect of cumulative exposure to tobacco smoking on DNA methylation, we performed a sensitivity analysis on the identified CpG sites in current smokers with packyears per 10 year as exposure. To assess the effect of discontinuation of tobacco smoking exposure, we performed a sensitivity analysis on the identified CpG sites in former smokers using cessation time per 10 years as exposure. The robust Bonferroni-corrected p-value for both analyses was 3.3 × 10−3 (0.05/15).
