Figure 4.

The buccal signature of smoky coal exposure is modulated throughout the intra- and extra-thoracic airway epithelium of current smokers versus never smokers. The behavior of the 282-gene smoky coal signature derived from the 35 Xuanwei and Fuyuan females was evaluated in independent gene-expression datasets generated from buccal biopsies (GSE17913), nasal brushings (GSE8987) and bronchial airway brushings (GSE994) collected from current smokers and never smokers. For each dataset, the smoky coal signature was collapsed into a composite metagene score and projected into never smokers and current smokers. *P < 0.05 via one-tailed t test.