26-Hydroxycholesterol plays a significant role in cholesterol metabolism and serves as an intermediate in the biosynthesis of bile acids. It is involved in the regulation of cholesterol homeostasis through activation of liver X receptors (LXRs), which control the expression of genes related to lipid metabolism and transport. Due to its ability to cross the blood-brain barrier, it is also implicated in brain cholesterol turnover and has been studied in the context of neurodegenerative diseases such as Alzheimer's. Elevated levels have been associated with certain metabolic disorders, making it a potential biomarker for diagnosing and monitoring diseases linked to cholesterol dysregulation. Additionally, it modulates immune responses and inflammation, suggesting possible relevance in autoimmune and cardiovascular conditions.