Meta-regression of smoking percent in lung cancer patients on in-allele risk estimates of <i>CHRNA3</i> gene rs1051730 (A) and <i>AGPHD1</i> gene rs8034191 (B) polymorphisms for occurrence of lung cancer.

<p>For each study, OR is shown by the middle of the blue solid circle whose upper and lower extremes represent the corresponding 95% CI. OR values were calculated for the current smokers against nonsmokers (including former smokers) when available or ex-smokers against never-smokers otherwise. The green dotted line is plotted by fitting OR and smoking percent in cases for the included studies.