In recent years, the incidence of adenocarcinoma has surpassed that of SCC.49 This may be due to changes in cigarette composition and smoking method.50 Technological advancements have shifted cases from large cell carcinoma to adenocarcinoma due to improvements in identifying peripheral pulmonary lesions, modifications in the WHO classification, and enhancements in staining mucin-producing cells.51 Another factors that might contribute to the increase in adenocarcinoma cases is air pollution, particularly nitrogen oxides.52 The gene discussed is MUC5AC; the disease is adenocarcinoma.