Passage Summary: There is a specific gene that smoke can turn 'on' to cause cancer, but even if that gene stays 'off,' smokers still face the same high risk of getting sick.

Reasoning: Cigarette smoke can trigger a specific gene to cause cancer, yet smokers who do not have this specific genetic reaction are still just as likely to get cancer as those who do.

Analysis: Since this is a 'Must be True' question, we need to find a deduction that is logically guaranteed by the facts provided. If the risk of cancer remains high even when this specific gene-metabolizing pathway is not activated, then there must be other ways that smoking causes cancer. The gene-based pathway described is clearly not the exclusive cause of the disease in smokers. Look for an answer choice that suggests smoking has multiple mechanisms for inducing lung cancer.