CHRNA5 and lung cancer: Thus, to determine whether or not genetic variations in the 15q25.1 lung cancer susceptibility locus are implicated in the carcinogenesis of cigarette smoking-mediated cancer risk other than lung cancer, we evaluated the association between the CHRNA5 rs3841324 polymorphism and NPC risk in general and in subgroups of subjects stratified by age, gender, cigarette smoking, alcohol consumption, and pathology, and explored the joint effect between CHRNA5 rs3841324 and cigarette smoke exposure on NPC risk with 400 patients newly diagnosed with NPC and 491 cancer-free healthy controls.