Figure 2
From: Testing gene-environment interactions in gene-based association studies
Joint testing of gene-environment interaction and main effects. The Q-Q plots compare the distribution of association –log10p-values for gene KDR (left panel) and FLT1 (right panel) derived from model (10) (circles) and model (14) (triangles) adjusted for 15 principal components (solid triangles and circles) or 200 principal components (open triangles and circles).