CYP2A6 is expressed primarily in the liver and is responsible for the metabolism of a wide range of compounds, including drugs, environmental toxins, and other xenobiotics. For example, CYP2A6 is involved in the metabolism of nicotine, as well as certain drugs used to treat heart disease, psychiatric disorders, and other medical conditions.

In some cases, variations in CYP2A6 activity can affect the efficacy and safety of drugs, and this is why it is important to understand the role of CYP2A6 in drug metabolism. For example, individuals with high CYP2A6 activity may metabolize drugs more rapidly, leading to reduced efficacy and increased risk of adverse effects, while individuals with low CYP2A6 activity may metabolize drugs more slowly, leading to increased efficacy and reduced risk of adverse effects.