However, exposure of Xpc deficient mice to chronic cigarette smoke and carcinogens, including urethane, MCA-BHT, 2-acetylaminofluorene (AAF) and NOH-AAF leads to lung adenocarcinoma development (42, 131), and with advanced age and chronic cigarette smoke, Xpc deficient mouse lungs develop an increase in lung compliance and alveolar rarefication similar to that seen in emphysema, a lung disease which predisposes to lung cancer (66). The gene discussed is XPC; the disease is pulmonary emphysema.