Chunk #0 — Introduction

Source

Rare nonsynonymous variants in alpha-4 nicotinic acetylcholine receptor gene protect against nicotine dependence.

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It is estimated that 18.1% of total US deaths were caused by tobacco in 2000, which makes tobacco smoking the leading cause of mortality (1). Despite increasing awareness of the health risks caused by smoking and efforts at tobacco-use prevention and control, the prevalence of smoking has declined slowly.