Fig. 3

Change in epigenetic age acceleration after smoking cessation in airway cells, lung tissue and merged (for airway cells) groups. a, b Comparison of epigenetic age acceleration between non-smokers, smokers, and ex-smokers in airway cells (a) and lung tissue (b). c A scatter plot of epigenetic age (x-axis) against chronological age (y-axis) in the airway cells (Fig. 1b). Blue circles indicate now-non-smokers (merge of non-smokers and ex-smokers) and red triangles indicate smokers. The dashed line is the diagonal where epigenetic age equals to chronological age, the blue solid line is the regression of DNAm age on chronological age for now-non-smokers, and the black solid line is the regression of DNAm age on chronological age for all of smokers and now-non-smokers. d–f The comparison of chronological age (d), AccelerationDiff value (e), and AccelerationResidual value (f) between smokers and now-non-smokers, as updates of Fig. 2d–f, where ex-smokers were not included in analysis