CHRNA5 and chronic obstructive pulmonary disease: The cumulative evidence for associations between six variants and LC or COPD risk was shown to be strong (28 significant associations: CHRNA3 rs1051730, CHRNA3 rs6495309, and CHRNA5 rs16969968 with COPD risk and CHRNA3 rs1051730, CHRNA3 rs578776, CHRNA3 rs6495309, CHRNA3 rs938682, CHRNA5 rs16969968, and CHRNA5 rs588765 with LC risk), and the cumulative evidence for associations between five SNPs (12 associations) and LC or COPD risk was moderate.