Reaction catalyzed by 3-oxosteroid 1-dehydrogenase (1.3.99.4)

		+			=			+
	9alpha-hydroxy-4-androstene-3,17-dione	+		2,6-dichlorophenol-indophenol	=		9alpha-hydroxy-1,4-androstadiene 3,17-dione	+		reduced 2,6-dichlorophenol-indophenol