Functional Classification Smoked vs Control Smoked+VitA vs Smoked Smoked+VitA vs Control VitA vs Control Cell division 3(+) 2(-) 1(+) . Apoptosis 1(+) . 1(+) 2 (+) Growth factor . 2(-) . . Cell adhesion 1(+) 2(-) . . Tumor suppressor inhibitor . 1(-) . . Tumor suppressor 1 (-) . 1(-) . Transcription factor 3(+) 1(-) . 1(+) Vitamin A metabolism . 2(-) . .

Table 3: Summary of functional classification for the statistical significantly expressed genes in the lungs corresponding to Table 1. Each number indicates the count of statistically significant genes. (+) indicates up-regulation while (-) indicates down-regulation.