CBR3 catalyzes the reduction of a large number of biologically and pharmacologically active carbonyl compounds to their corresponding alcohols. CBR3 is one of several monomeric NADPH-dependent oxidoreductases. Furthermore， CBR3 contains 3 exons spanning 11.2 kilobases and is strongly linked to another carbonyl reductase gene， the CBR1. It was suggested that CBR3 mediates 9-cis-retinoic acid-induced cytostatis and is a potential prognostic marker for oral malignancy.
CBR3 is identified in the ovary， pancreas， intestine， colon， kidney， brain， thymus， lung， heart， liver， spleen， leukocyte， prostate and the testis.
Polymorphisms in CBR3 may give an explanation to interindividual and interethnic variability of doxorubicin pharmacokinetics and pharmacodynamics.
