<p>Steroid hormones like estrogen (E2) and testosterone are associated with an increased incidence of breast cancer. To understand this association, it is crucial to explore the metabolism of these hormones in detail, as specific metabolites, produced by certain cytochrome P450 (CYP) enzymes, may influence the development of breast cancer. In addition to well-known enzymes, such as CYP1B1, which are correlated with breast cancer risk, there is growing evidence suggesting that the enzyme CYP2B6 might have a&#xa0;protective effect. While the exact mechanism by which CYP2B6 exerts its protective influence is not yet fully understood, it may be related to an indirect effect on the E2 metabolism through the breakdown of testosterone. The metabolism of these hormones plays a&#xa0;significant role in breast cancer and understanding it could lay the basis for targeted metabolic biomarker analysis in breast cancer therapy and prevention.</p>