In this issue of Clinical Science, Agema and co-workers report the results of a genetic association study of eNOS (endothelial nitric oxide synthase) gene polymorphisms (-786T --> C, intron 4b --> a and Glu298 --> Asp) in patients with angiographic CAD (coronary artery disease), and/or prior MI (myocardial infarction) and a group of healthy population-based controls. However, the findings of this study appear to contradict previous studies published on the eNOS polymorphisms, and this commentary will attempt to resolve the inconsistency in such genetic association studies.