MDM2 and lung cancer: However, the crude OR without stratification showed no significant association between smoking and lung cancer (OR (95% CI) = 1.908 (0.793–4.589), P = 0.149) and failed to reveal this relationship under the confounding of the MDM2 rs2279744 polymorphism, further confirming the importance of the standard stratification analysis in controlling confounder effects and revealing the real relationship between exposure and outcome.