These features make genetic variants suitable candidates as instrumental variables, which can help estimate the causal effects of modifiable exposures on outcomes.7 For example, the rs1229984 variant in the alcohol dehydrogenase 1B gene (ADH1B) has been used as an instrument to investigate the causal role of alcohol in cardiovascular disease.10 Given these advantages, MR studies have increased in popularity and have begun to inform understanding of disease causation. Here, ADH1B is linked to cardiovascular disorder.