title: One author replies.
authors.affiliation: Department of Epidemiology, School of Public Health, Wuhan University, Wuhan, China.
authors.forename: Zhi-Jiang
authors.initials: ZJ
authors.lastname: Zhang
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008175:Lung Neoplasms / Q000453:epidemiology*; D008687:Metformin / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin