NFE2L2 and pulmonary emphysema: To determine the molecular mechanisms underlying CS-induced lung emphysema, we applied RCR to transcriptomic data sets derived from lungs of five mouse genotypes (C57BL/6, ApoE−/−, A/J, Nrf2−/− and CD1), susceptible to emphysema development following a prolonged (5–6 months) exposure to CS.