Cholesterol-5,6-epoxides: Chemistry, biochemistry, metabolic fate and cancer

► Cholesterol-5,6-epoxides (5,6-ECs) are major autoxidation products of cholesterol. ► 5,6-ECs are not spontaneous alkylating substances. ► 5,6-ECs are not direct mutagenic or carcinogenic substances. ► Cholestane-3,5,6-triol forms a mutagenic substance upon oxidation. ► 5,6α-EC can give a product of addition with histamine under catalytic conditions.