The UGTs (EC 2.4.1.17) serve a major role in the conjugation and subsequent elimination of potentially toxic xenobiotics and endogenous compounds. UGT2B7 has unique specificity for 3,4-catechol estrogens and estriol, suggesting that it may play an important role in regulating the level and activity of these potent estrogen metabolites. Its subcellular location is the microsome.