**Figure 1.** **Stratified Q-Q plots and fold-enrichment plots.** Stratified Q-Q plots of nominal vs. empirical -log10(*p*) values in principal trait below the standard GWAS threshold of *p* ≤ 5 × 10^{−8} as a function of the significance of the association with conditional trait at the level of *p* ≤ 1, *p* ≤ 0.1, *p* ≤ 0.01, *p* ≤ 0.001, and *p* ≤ 0.0001, respectively. (**A**) CAD as a function of the significance of the association with BW, and (**B**) BW as a function of the significance of the association with CAD. Fold-enrichment plots of enrichment vs nominal -log10(*p*) values (corrected for inflation) corresponding to levels of *p* ≤ 1, *p* ≤ 0.1, *p* ≤ 0.01, ≤ 0.001, respectively in (**C**) CAD below the standard GWAS threshold of *p* ≤ 5 × 10^{−8} as a function of significance of the association with BW; and in (**D**) BW below the standard GWAS threshold of *p* ≤ 5 × 10^{−8} as a function of significance with CAD. Dashed lines indicate the null-hypothesis.