Causal assumptions as a directed acyclic graph.

<p>Diagram of causal relationships between genetic variants, risk factors (low-density lipoprotein cholesterol, LDL-c; high-density lipoprotein cholesterol, HDL-c; and triglycerides), confounders, and disease (coronary artery disease, CAD). Although confounders (common causes of a risk factor and the outcome) are represented as a single variable for simplicity, each risk factor may have a different set of confounders.