Enables cholesterol 7-alpha-monooxygenase activity. Involved in several processes, including bile acid biosynthetic process; cellular response to cholesterol; and regulation of lipid biosynthetic process. Located in intracellular membrane-bounded organelle. Biomarker of alcoholic hepatitis; cholestasis; extrahepatic cholestasis; and non-alcoholic steatohepatitis. Orthologous to human CYP7A1 (cytochrome P450 family 7 subfamily A member 1). [provided by Alliance of Genome Resources, Apr 2022]