Figure 3From: Genetic susceptibility for chronic bronchitis in chronic obstructive pulmonary disease Manhattan plots of –log 10 P values for meta-analysis of three cohorts for (A) COPD subjects with chronic bronchitis (CB) versus smoking controls and (B) CB versus no CB within COPD subjects, after adjustment for age, sex, pack-years of cigarette smoking and genetic ancestry using principal components. Back to article page