A cholesterol metabolite and intermediate in the biosynthesis of chenodeoxycholic acid; induces apoptosis in cornea and lens epithelial cells at 10 μg/ml in vitro; increases serum and liver cholestanol levels and leads to corneal opacities and gallstones in mice following dietary administration at 1%; leads to cholestanol deposition in the cerebellum in rats following dietary administration at 1%; levels are increased in plasma of patients with CTX