CBR4 is a member of the short-chain dehydrogenase/reductase family. CBR4 has a role in biosynthesis of fatty acids in the mitochondria and a broad substrate specificity and reduces 9,10-phenanthrenequinone, 1,4-benzoquinone and a range of other o-quinones and p-quinones(in vitro). CBR4 formation of a heteroteramer with HSD17B8 has NADH-dependent 3-ketoacyl-acyl carrier protein reductase activity for o- and p-quinones.