Figure 8.

Functional categorization of small airway epithelium (SAE) ubiquitous and SAE-enriched smoking-responsive genes. The smoking-responsive genes (p < 0.05) of the ubiquitous and SAE-enriched groups were assigned function based on Gene Ontology classification and searches of NCBI databases. The 9 functional categories chosen accounted for the largest fraction of the genes that could be assigned functional categories. For each category, the genes were divided into smoking-induced and smoking-repressed and the log₁₀ of absolute change (RPKM smoker - RPKM nonsmoker) was plotted. Genes are divided by category and ordered within each category by decreasing change in expression level. Red - down-regulated; blue - up-regulated. Note that for both ubiquitous and SAE-enriched genes, a higher fraction of genes in most categories are down-regulated, and that most up-regulated genes are in the SAE-enriched subgroup.