Fig. 4
From: Effect of tobacco smoking on the epigenetic age of human respiratory organs
DNA methylation levels in non-smokers, smokers, and ex-smokers. The color scales indicate normalized DNA methylation levels, β value. The upper part of the heat map shows gene site clusters in airway cell samples, filtered by a methylation level difference (p < 0.05) between sites; the lower part, in lung tissue samples, filtered by a methylation level difference (p < 0.01) between sites. Three sites shared by airway cells and lung tissue are marked with black boxes