Indole-2-monooxygenase (, BX2 (gene), CYP71C4 (gene)) is an enzyme with systematic name indole,NAD(P)H:oxygen oxidoreductase (2-hydroxylating). This enzyme catalyses the following chemical reaction
Indole-2-monooxygenase is involved in the biosynthesis of protective and allelopathic benzoxazinoids in some plants.