CYP8B1 (cytochrome P450 family 8 subfamily B member 1) is a microsomal enzyme that catalyzes the 12α-hydroxylation of bile acid intermediates, playing a crucial role in primary bile acid biosynthesis and homeostasis 1. The enzyme specifically converts 7α-hydroxy-4-cholesten-3-one to facilitate cholic acid synthesis, controlling the balance between cholic acid and chenodeoxycholic acid production 2. CYP8B1 expression is regulated by multiple pathways, including PPARα signaling, FXR-mediated mechanisms, and microRNA networks, with reduced expression favoring hydrophilic bile acid composition 345. The enzyme's activity is critical for cholesterol homeostasis and dietary lipid absorption, with dysregulation contributing to cholestatic liver diseases 6. In hepatocellular carcinoma, CYP8B1 expression is significantly decreased compared to normal tissue, and reduced expression correlates with poor prognosis 7. Overexpression of CYP8B1 in cancer cells inhibits proliferation and promotes apoptosis through modulation of cell cycle regulators and apoptotic pathways 7. The enzyme represents both a therapeutic target for metabolic disorders and a potential prognostic biomarker in liver cancer.